The invention discloses a flash translation layer system, which relates to the field of flash memory. The flash translation layer system comprises an address translation module and a write operation processing module, the address translation module is used for translating logical addresses into physical addresses, physical blocks in the system include data blocks, log blocks and free blocks, logic blocks correspond to the data blocks one by one, each logic block at most corresponds to two log blocks, each log block corresponds to a plurality of logic blocks, and the write operation processing module is used for processing write operation of flash media. By the aid of the flash translation layer system, garbage collection frequency and data copying amount in a garbage collection process are balanced, erasing frequency and the data copying amount in the garbage collection process are reduced, the flash life is ensured, and the flash performance is improved.