Abstract: A new NAND flash memorygarbage collection algorithm based on invalid page age was proposed to solve the problems of the existing NAND flash garbage collection algorithm, which considered the efficiency of the collection and the separation of hot and cold data. This algorithm proposeda new victim block selection strategy which calculated collection cost use number and age of invalid pages, while use static wear to ensure wear leveling.In addition, the algorithm redefines the heat calculation formula of the logical page data, and proposes to divide the valid data into hot data, sub-hot data, sub-cold data and cold data by using the dynamically adjusted threshold value. Different types of data are transferred to different idle blocks, which effectively realizes the separation of cold and hot of the logical page data.The simulation results show that compared with GR, CB, CAT, FaGC and FaGC+ algorithms, the proposed algorithm achieves minimum collection cost and better results in wear leveling.