The security monitoring system of Beijing Long Sen Video Technology Co., Ltd. is an independent and complete system, which uses optical fiber, coaxial cable or microwave to transmit video signals in its closed loop, and forms an independent and complete system from camera shooting to image display and recording. It can reflect the monitored object in real time, vividly and truly, which not only greatly extends the observation distance of human eyes, but also expands their functions. It can replace manual monitoring for a long time in harsh environment, so that people can see the actual situation at the monitoring site and record it through a video recorder. At the same time, the alarm system equipment alarms the illegal intrusion, and the generated alarm model is input to the alarm host, which triggers the monitoring system to record. security monitoring system