A non-volatile memory access method and system, and a non-volatile memory controller are provided for accessing a plurality of physical blocks in a non-volatile memory chip, and each physical block has a plurality of physical pages. The method includes determining whether there is enough space in a first physical block to write a plurality of specific physical pages when data stored in one of the specific physical pages are to be updated; and writing valid data and data to be updated into the first physical block when the first physical block has enough space to write the specific physical pages.