Abstract: Aimed at the high security requirements for the unattended vending machine，a design of USB communication electromagnetic lock control sysltem based on SCM is proposed. With SILl wzU 2s >LCNPas the control core,and the development process of the electromagnetic lock control system based on USB communication，the hardware design method and software design method of the syslem are introduced indetail. After testing and application，the system can meet the control technical requirements of electro-magnetic lock. It is safe，reliable and cost-effective.

Key words: single chip microcomputer ( SCM ) , USB data communication , electromagnetic lock , control system