The invention discloses a page caching method suitable for a DRAM/PRAM mixed main memory architecture and a mixed main memory architecture system, wherein the page caching method comprises the following steps: a mixed main memory system receives a page operation request, and a page with a page writing request is put into a DRAM when the page operation request is the page writing request; a page with a page reading request is put into a PRAM when the page operation request is the page reading request; and the mixed main memory system screens a write-intensive cached page according to a write-intensive flag site of the page, and the write-intensive cached page is transferred into the DRAM from the PRAM to carry out caching. The page caching method alleviates delay caused by PRAM writing operation, lowers the performance loss of the main memory system and achieves the purpose of prolonging the service life of the PRAM at the same time.