Fully compressed image, digitally processed color/black and white picture splitter; four-way (or nine or sixteen-way) video input with four-way (or nine or sixteen-way) ring-connected output; built-in adjustable time Sequential switcher and independent switching output. According to the number of the camera, the full-screen picture is switched in order, and the display time of the sensitive road picture can be optimized and programmed by the user himself; high resolution and real-time update rate. The picture index is 512×512 pixels, and the update rate is 25-30 fields/second. When the tape is played back, it can realize 1/4 (or 1/9, 1/16) screen to full screen zoom (revert to real-time full screen) Compatible with standard SUPER-VHS recorders (some also have S-VHS interface); there is an alarm input/output interface that can be linked with the alarm system. When the alarm is activated, the full screen screen can be called and an alarm output signal can be generated to start the recorder or other related equipment. That is to say, when the alarm signal is generated, the scene of the area related to the alarm will be displayed in full screen and automatically recorded. The user can set the duration of the alarm and the duration of the recording. The number of alarm input interfaces is the same as the number of screen inputs.