fumei my understanding is that the OP wants the number in the header to be the page number in the section, and in the footer the page number in the document.

Yes, and I have in front of me a document with two sections. The total number of pages (Section and Section 2) is 17. Section 2 starts at the 17th page.

In the header of Section 2, the first page shows its page number as 1 - as Section 2 restarts the count at 1. The value is Page Number.

In the footer - ALSO in Section 2 - the number shows as 17. The value is Number of Pages.

Page Number reflects the page number of the current section.
Number of Pages reflects the number of pages in the document.