Create Site Columns & Site Content Types by PowerShell

• Take care all columns Web id & Lookup Filed List id
  If you have Lookup field first create list and get id
  
  

-Get Site Columns-

$sourceWeb = Get-SPWeb http://yoursite.export.com
$xmlFilePath = "C:\Backup\Script-SiteColumns.xml"

#Create Export Files
New-Item $xmlFilePath -type file -force

#Export Site Columns to XML file
Add-Content $xmlFilePath ""
Add-Content $xmlFilePath "`n"
$sourceWeb.Fields | ForEach-Object {
    if ($_.Group -eq "your export group column") {
        Add-Content $xmlFilePath $_.SchemaXml
    }
}
Add-Content $xmlFilePath "
"
$sourceWeb.Dispose()

-Create Site Columns-

$destWeb = Get-SPWeb http://yoursite.import.com
$installPath = "c:\Backup"
$fieldsXML = [xml](Get-Content($installPath + "\Script-SiteColumns.xml"))

$fieldsXML.Fields.Field | ForEach-Object {
    
    #Configure core properties belonging to all column types
    $fieldXML = '
    Name="' + $_.Name + '"
    ID="' + $_.ID + '"
    Description="' + $_.Description + '"
    DisplayName="' + $_.DisplayName + '"
    StaticName="' + $_.StaticName + '"
    Group="' + $_.Group + '"
    Hidden="' + $_.Hidden + '"
    Required="' + $_.Required + '"
    Sealed="' + $_.Sealed + '"'
    
    #Configure optional properties belonging to specific column types – you may need to add some extra properties here if present in your XML file
    if ($_.ShowInDisplayForm) { $fieldXML = $fieldXML + "`n" + 'ShowInDisplayForm="' + $_.ShowInDisplayForm + '"'}
    if ($_.ShowInEditForm) { $fieldXML = $fieldXML + "`n" + 'ShowInEditForm="' + $_.ShowInEditForm + '"'}
    if ($_.ShowInListSettings) { $fieldXML = $fieldXML + "`n" + 'ShowInListSettings="' + $_.ShowInListSettings + '"'}
    if ($_.ShowInNewForm) { $fieldXML = $fieldXML + "`n" + 'ShowInNewForm="' + $_.ShowInNewForm + '"'}
        
    if ($_.EnforceUniqueValues) { $fieldXML = $fieldXML + "`n" + 'EnforceUniqueValues="' + $_.EnforceUniqueValues + '"'}
    if ($_.Indexed) { $fieldXML = $fieldXML + "`n" + 'Indexed="' + $_.Indexed + '"'}
    if ($_.Format) { $fieldXML = $fieldXML + "`n" + 'Format="' + $_.Format + '"'}
    if ($_.MaxLength) { $fieldXML = $fieldXML + "`n" + 'MaxLength="' + $_.MaxLength + '"' }
    if ($_.FillInChoice) { $fieldXML = $fieldXML + "`n" + 'FillInChoice="' + $_.FillInChoice + '"' }
    if ($_.NumLines) { $fieldXML = $fieldXML + "`n" + 'NumLines="' + $_.NumLines + '"' }
    if ($_.RichText) { $fieldXML = $fieldXML + "`n" + 'RichText="' + $_.RichText + '"' }
    if ($_.RichTextMode) { $fieldXML = $fieldXML + "`n" + 'RichTextMode="' + $_.RichTextMode + '"' }
    if ($_.IsolateStyles) { $fieldXML = $fieldXML + "`n" + 'IsolateStyles="' + $_.IsolateStyles + '"' }
    if ($_.AppendOnly) { $fieldXML = $fieldXML + "`n" + 'AppendOnly="' + $_.AppendOnly + '"' }
    if ($_.Sortable) { $fieldXML = $fieldXML + "`n" + 'Sortable="' + $_.Sortable + '"' }
    if ($_.RestrictedMode) { $fieldXML = $fieldXML + "`n" + 'RestrictedMode="' + $_.RestrictedMode + '"' }
    if ($_.UnlimitedLengthInDocumentLibrary) { $fieldXML = $fieldXML + "`n" + 'UnlimitedLengthInDocumentLibrary="' + $_.UnlimitedLengthInDocumentLibrary + '"' }
    if ($_.CanToggleHidden) { $fieldXML = $fieldXML + "`n" + 'CanToggleHidden="' + $_.CanToggleHidden + '"' }
    if ($_.List) { $fieldXML = $fieldXML + "`n" + 'List="' + $_.List + '"' }
    if ($_.ShowField) { $fieldXML = $fieldXML + "`n" + 'ShowField="' + $_.ShowField + '"' }
    if ($_.UserSelectionMode) { $fieldXML = $fieldXML + "`n" + 'UserSelectionMode="' + $_.UserSelectionMode + '"' }
    if ($_.UserSelectionScope) { $fieldXML = $fieldXML + "`n" + 'UserSelectionScope="' + $_.UserSelectionScope + '"' }
    if ($_.BaseType) { $fieldXML = $fieldXML + "`n" + 'BaseType="' + $_.BaseType + '"' }
    if ($_.Mult) { $fieldXML = $fieldXML + "`n" + 'Mult="' + $_.Mult + '"' }
    if ($_.ReadOnly) { $fieldXML = $fieldXML + "`n" + 'ReadOnly="' + $_.ReadOnly + '"' }
    if ($_.FieldRef) { $fieldXML = $fieldXML + "`n" + 'FieldRef="' + $_.FieldRef + '"' }   

    $fieldXML = $fieldXML + ">"
    
    #Create choices if choice column
    if ($_.Type -eq "Choice") {
        $fieldXML = $fieldXML + "`n"
        $_.Choices.Choice | ForEach-Object {
           $fieldXML = $fieldXML + "`n" + $_ + ""
        }
        $fieldXML = $fieldXML + "`n
"    }
    
    #Set Default value, if specified  
    if ($_.Default) { $fieldXML = $fieldXML + "`n" + $_.Default + "" }
    
    #End XML tag specified for this field
    $fieldXML = $fieldXML + "
"    
    #Create column on the site
    $destWeb.Fields.AddFieldAsXml($fieldXML.Replace("&","&"))
    write-host "Created site column" $_.DisplayName "on" $destWeb.Url
    
    $destWeb.Dispose()
}

-Get Site Column & Content TYPES-

$sourceWeb = Get-SPWeb http://yoursite.export.com
$xmlFilePath = "C:\Backup\Script-SiteContentTypes.xml"

#Create Export File
New-Item $xmlFilePath -type file -force

#Export Content Types to XML file
Add-Content $xmlFilePath ""
Add-Content $xmlFilePath "`n"
$sourceWeb.ContentTypes | ForEach-Object {
    if ($_.Group -eq "your Export Content Type") {
        Add-Content $xmlFilePath $_.SchemaXml
    }
}
Add-Content $xmlFilePath "
"
$sourceWeb.Dispose()

-Create Site Columns And Content Types-

$destWeb = Get-SPWeb http://yoursite.import.com
$xmlFilePath = "C:\Backup\Script-SiteContentTypes.xml"
#Create Site Content Types
$ctsXML = [xml](Get-Content($xmlFilePath))
$ctsXML.ContentTypes.ContentType | ForEach-Object {

    #Create Content Type object inheriting from parent
    $spContentType = New-Object Microsoft.SharePoint.SPContentType ($_.ID,$destWeb.ContentTypes,$_.Name)
    
    #Set Content Type description and group
    $spContentType.Description = $_.Description
    $spContentType.Group = $_.Group
    
    $_.Fields.Field  | ForEach-Object {
        if(!$spContentType.FieldLinks[$_.DisplayName])
        {
            #Create a field link for the Content Type by getting an existing column
            $spFieldLink = New-Object Microsoft.SharePoint.SPFieldLink ($destWeb.Fields[$_.DisplayName])
        
            #Check to see if column should be Optional, Required or Hidden
            if ($_.Required -eq "TRUE") {$spFieldLink.Required = $true}
            if ($_.Hidden -eq "TRUE") {$spFieldLink.Hidden = $true}
        
            #Add column to Content Type
            $spContentType.FieldLinks.Add($spFieldLink)
        }
    }
    
    #Create Content Type on the site and update Content Type object
    $ct = $destWeb.ContentTypes.Add($spContentType)
    $spContentType.Update()
    write-host "Content type" $ct.Name "has been created"
}

$destWeb.Dispose()

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Referenced : http://get-spscripts.com/2011/02/export-and-importcreate-site-content.html

Thanks man :)