网上得来的：
下面是一个追加pdf的函数， 合并也一样的
' Append PDF files to a single PDF file
' Alvin 2/10/2007
'Thanks for the idea of johnsonm
Public Function AppendPDFs(arrPdfFiles() As String, strFileName As String) As Boolean
Dim AcroApp As CAcroApp
Dim avCodeFile As CAcroAVDoc
Dim PDDoc1 As CAcroPDDoc
Dim PDDoc2 As CAcroPDDoc
Dim i As Long
Dim lngPage As Long
Dim lngPageNum1 As Long
Dim lngPageNum2 As Long
Dim lngPageNum3 As Long
lngPageNum1 = 0
lngPageNum2 = 0
lngPageNum3 = 0
'Start Acrobat in the background
Set AcroApp = CreateObject("AcroExch.App")
AcroApp.Hide
Set avCodeFile = CreateObject("AcroExch.AVDoc")
avCodeFile.Open strFileName, strFileName
Set PDDoc1 = avCodeFile.GetPDDoc
lngPageNum1 = PDDoc1.GetNumPages
lngPageNum3 = 0
For i = LBound(arrPdfFiles) To UBound(arrPdfFiles)
Set PDDoc1 = avCodeFile.GetPDDoc
Set PDDoc2 = CreateObject("AcroExch.PDDoc")
PDDoc2.Open arrPdfFiles(i)
lngPage = PDDoc1.GetNumPages - 1
If lngPage < 0 Then lngPage = 0
PDDoc1.InsertPages lngPage, PDDoc2, 0, PDDoc2.GetNumPages, 0
lngPageNum3 = lngPageNum3 + PDDoc2.GetNumPages
Next i
PDDoc1.Save 1, strFileName
lngPageNum2 = PDDoc1.GetNumPages
PDDoc1.Close
PDDoc2.Close
avCodeFile.Close 0
'Exit Acrobat
AcroApp.Exit
Set AcroApp = Nothing
Set avCodeFile = Nothing
Set PDDoc1 = Nothing
Set PDDoc2 = Nothing
If lngPageNum2 - lngPageNum1 = lngPageNum3 Then
AppendPDFs = True
Else
AppendPDFs = False
End If
End Function
