According to Nand Flash memory bad block problem, this paper proposed a automatic check scheme to deal with bad block based on STM32. Without increasing the external device, through its internal flexible static memory controller, sends the corresponding data, address, control signals, to rapid access Flash memory. Its part circuit schematic diagram and C language program code was introduced. The design has been successfully realized the function of automatic checking the invalid block finally, and has the advantages of simple operation, fast detection speed, high accuracy rate, and can read the ID number of Flash to get the performance of the memory. And the design also can write and read 2GB data.