A school bus radar system includes a main unit mounted in the school bus, and two radars protrudingly arranged on the bus body of the school bus in a tilted manner and respectively electrically connected to the main unit. When the main unit is switched to a monitoring mode, the main unit generates a radar activation signal to activate the radars in generating a signal, making the signals generated by the monitoring sources of the radars form an intersection network. The monitoring source of each radar defines a normal line. Accordingly, the intersection type three-dimensional spatial monitoring network of the radar system of the present invention is proposed for individual warnings to facilitate the driver making good judgments or stopping the running school bus in an emergency.