The invention provides a vehicle-mounted monitoring system with a good monitoring effect. The vehicle-mounted monitoring system comprises a camera, a communication antenna, a vehicle-mounted monitoring device, a memory and a display device, wherein the camera is mounted on the vehicle and is used for shooting a monitoring image on the periphery of the vehicle and transmitting the monitoring imageto the vehicle-mounted monitoring device via the communication antenna, the communication antenna is mounted on the top of the vehicle and is used for realizing the network communication between the vehicle-mounted monitoring device and the camera, the vehicle-mounted monitoring device is mounted in the vehicle, is separately connected with the communication antenna and the memory and is used forcollecting the monitoring image output by the camera by the communication antenna in real time, processing the monitoring image, and storing the monitoring image in the memory, the memory is mounted in the vehicle and is used for storing the processed monitoring image, and the display device is mounted in the vehicle and is used for displaying the monitoring image stored in the memory. The vehicle-mounted monitoring system has the beneficial effects of being able to accurately obtaining the monitoring information on the periphery of the vehicle.