Abstract: The mass capacity memory based on NAND Flash is widely used in space storage fields recently. However,due to a variety of condition constrain and bad blocks can be produced,so the reliability of mass capacity storage can not be assured especially in severe environment.A new design plan is proposed to realize the high reliability mass capacity memory.The core technology are reasonable bad block management,triplication redundancy reading and writing of key data through SRAM,warm standby of Flash arrays and checking of data playback.The experiment result shows that the system data will not be caused to incomplete,and the cost of the whole storage system is lower than the current onboard memory.