Security access control system has become an extremely important part of security system. The fundamental reason is that it takes the initiative to replace the passive monitor, such as CCTV, burglar alarms, to control main channels to prevent criminals from entering through normal channels, and that it is able to control access doors to deter crime or reduce losses. In recent years, GPRS access control system has been popular, applied to postal system, power supply system, banking system, residential area, hotels, etc.. It greatly improves security management efficiency.