#网上所得非原创

function split($inFile, $outPrefix, [Int32] $bufSize){

$stream = [System.IO.File]::OpenRead($inFile)
$chunkNum = 1
$barr = New-Object byte[] $bufSize

while( $bytesRead = $stream.Read($barr,0,$bufsize)){
$outFile = "$outPrefix$chunkNum"
$ostream = [System.IO.File]::OpenWrite($outFile)
$ostream.Write($barr,0,$bytesRead);
$ostream.close();
echo "wrote $outFile"
$chunkNum += 1
}
}

split ‘F:\log\u_ex141125.log‘ ‘F:\log\iis‘ 1000

Powershell split file