转自:http://word.mvps.org/FAQs/MacrosVBA/FindReplaceAllWithVBA.htm

When the Find or Replace utility on the Edit menu is used, it will find or replace text no matter where it appears in the document.  If you record that action however, it will only act on the text in the body of the document and it will have no effect on text that is in the headers or footers of the document, for example, or in a textbox, footnotes, or any other area that is outside the main body of the document.
This is well worth contacting http://support.microsoft.com/contactus/ about.
To use a macro to find or replace text no matter where it is located in the document, it is necessary to loop through each of the StoryRanges in the document.
There are 11 different types of stories that can be part of a document, corresponding to the following WdStoryType constants: 
wdCommentsStory, wdEndnotesStory, wdEvenPagesFooterStory, wdEvenPagesHeaderStory, wdFirstPageFooterStory, wdFirstPageHeaderStory, wdFootnotesStory, wdMainTextStory, wdPrimaryFooterStory, wdPrimaryHeaderStory, and wdTextFrameStory.
The following code will loop through the first story for each story type in the document, replacing all instances of the text that is to be replaced in the first story of each type:
Sub FindAndReplaceFirstStoryOfEachType()

Dim
myStoryRange As Range

For Each myStoryRange In ActiveDocument.StoryRanges
    With myStoryRange.Find
        .Text = "findme"
        .Replacement.Text = ""
        .Wrap = wdFindContinue
        .Execute Replace:=wdReplaceAll
    End With
Next myStoryRange

End Sub
(Note for those already familiar with VBA: whereas if you use Selection.Find, you have to specify all of the Find and Replace parameters, such as .Forward = True, because the settings are otherwise taken from the Find and Replace dialog's current settings, which are sticky, this is not necessary if using [Range].Find – where the parameters use their default values if you don't specify their values in your code).
As mentioned previously, the above code will only act upon the first story for each story type in the document. (The first Header, the first Text Box, and so on). If your document contains sections with un-linked headers and footers in them, or, for example, contains more than one Text Box, the code will not act upon the second and subsequent occurrences of each type of story. So to make sure that the code does act on each occurrence of the text, no matter where it appears, you have to make use of the NextStoryRange method as in the following code:
Sub FindAndReplaceAllStoriesHopefully()

Dim
myStoryRange As Range

For Each myStoryRange In ActiveDocument.StoryRanges
    With myStoryRange.Find
        .Text = "findme"
        .Replacement.Text = ""
        .Wrap = wdFindContinue
        .Execute Replace:=wdReplaceAll
    End With
    Do While Not (myStoryRange.NextStoryRange Is Nothing)
        Set myStoryRange = myStoryRange.NextStoryRange
        With myStoryRange.Find
            .Text = "findme"
            .Replacement.Text = ""
            .Wrap = wdFindContinue
            .Execute Replace:=wdReplaceAll
        End With
    Loop
Next myStoryRange

Problems with cycling through StoryRanges, and some workarounds

Some Headers can get missed out
Unfortunately, even this method doesn't work reliably if you have any blank Headers or Footers in your document. If, for example, you have a document in which the first section has a blank primary Header in the first section (such as might be the case for a report cover sheet), then none of the primary Headers in the subsequent sections will be checked! Another thing that is well worth contacting http://support.microsoft.com/contactus/ about.
One workaround for this is to design all your templates such that none of the Headers are blank – insert a space in any blank Headers. If doing so alters the layout of that section, apply a different style in that Header, so that it doesn't. There is really no other satisfactory workaround, for reasons that will be discussed in a separate article shortly.
Speed of the macro
Another problem with the above code is that it can be very slow if the document is large, or if it contains a large number of story ranges. This is especially a problem in Word 97. In Word 97, using Selection.Find is much faster than using [Range].Find. So you can speed up the above code up very significantly, in Word 97, by using the following instead:
Sub FasterFindAndReplaceAllStoriesHopefully()

Dim
myStoryRange As Range

'First search the main document using the Selection
 With Selection.Find
    .Text = "findme"
    .Replacement.Text = ""
    .Forward = True
    .Wrap = wdFindContinue
    .Format = False
    .MatchCase = False
    .MatchWholeWord = False
    .MatchWildcards = False
    .MatchSoundsLike = False
    .MatchAllWordForms = False
    .Execute Replace:=wdReplaceAll
 End With

'Now search all other stories using Ranges
For Each myStoryRange In ActiveDocument.StoryRanges
   If myStoryRange.StoryType <> wdMainTextStory Then
        With myStoryRange.Find
            .Text = "findme"
            .Replacement.Text = ""
            .Wrap = wdFindContinue
            .Execute Replace:=wdReplaceAll
        End With
        Do While Not (myStoryRange.NextStoryRange Is Nothing)
           Set myStoryRange = myStoryRange.NextStoryRange
            With myStoryRange.Find
                .Text = "findme"
                .Replacement.Text = ""
                .Wrap = wdFindContinue
                .Execute Replace:=wdReplaceAll
            End With
        Loop
    End If
Next myStoryRange

And the fastest, but flakiest, workaround ...

If you want your code to be as fast as doing a replace via the user interface, and/or if you want it to be completely immune to the headers get missed out if the first header is blank bug, the only solution is to call Word's Find and Replace dialog directly, by executing the menu button (using Word's Dialogs collection doesn't help); and using the SendKeys command to execute it. You can set the dialog's settings the way you want them by using the a With Selection.Find ... End With construct, with no .Execute command, before you execute the menu button. You would need to include DoEvents in your code to allow the command to complete it's search.
But using SendKeys is notoriously flaky, and especially so in this case, because the Find and Replace dialog is modeless; so this is usually not a good method. It is mentioned here for the sake of completeness.