The invention relates to a secure digital (SD) memory card hardware control device and a control method and belongs to the technical field of SD memory card control. The control device is composed of a register block, a state machine, an Avalon master port, an Avalon slave port, a cyclic redundancy check (CRC) 7 module and a CRC 16 module, and the SD memory card can be controlled for reading and writing a plurality of sectors each time without the interference of a central possessing unit (CPU). The control method provides a corresponding design method of a file allocation table (FAT) 16 file system, and the operation of the FAT 16 file system can be finally achieved on the SD memory card by writing a driving function of a hardware controller and constructing a file system operation function, so that the read and written SD memory card can directly exchange files with other platforms such as a computer. According to the SD memory card hardware control device and the control method, the read-write speed of the SD memory card and the use ratio of the CPU are greatly increased, and the file management of the SD memory card is facilitated; only data interfaces are required to be modified, and then the SD memory card hardware control device and the control method can be transplanted to other embedded systems; and the SD memory card hardware control device and the control method are broad in application prospects.