Abstract: The certain satellite communication system has played a positive and effective role in combating terrorism and maintaining stability, emergency-rescue and disaster-relief operations, security alert, maritime rights protection as well as handling border emergencies. From the point view of the multiple access control technique, this paper gives a brief introduction to the performance of a certain satellite communication system based on ALOHA access control protocol, and analyzes the main reason of hardly improving the rate of connection in the certain areas within certain periods for the user terminal stations. Then it proposes the modified implementation with the help of double clock ALOHA (DC-ALOHA) access control protocol. Based on the system throughput derived from the analysis method of mean cyclic period, the performance of system packet transmission has been improved via the combination of theoretical computation as well as computer simulation for DC-ALOHA access control protocol, and the rate of connection for the user terminal stations can also be increased.