My husband orderd to get his bank statements by post they told him it will take from 3 to 5 working days to get them ,my question is should he stamp every page ?as they told him in the bank that they are acceptable without stamp .
The bank's opinion on what is acceptable is irrelevant. They are not the authority issuing the visa.
You do not need to have every page signed/stamped, but each document itself should be (ideally, multi-page documents should have a header or footer that says "page [n] of [number of pages]"). He should take the statements to a local branch to have them signed/stamped, if they were not posted to him already with a stamp and signature. In general, all printed documents must have a stamp and signature of the issuing authority.