The invention discloses a bus fire extinguishing system. The bus fire extinguishing system is arranged in a bus and comprises a control cabinet, a water tank, a high-pressure pump, a motor, a main water pipe, branched water pipes, spraying heads, a temperature sensor and a smoke sensor; the high-pressure pump is connected with the water tank through a pipe, an output shaft of the motor is fixedly connected with an input shaft of the high-pressure pump, the main water pipe is connected to a water outlet of the high-pressure pump, a solenoid valve is installed on the main water pipe and connected with the control cabinet through a wire, the multiple branched water pipes are connected to the main water pipe, and a plurality of spraying heads are installed on each branched water pipe; and the temperature sensor is connected with the control cabinet through a wire, and the smoke sensor is connected with the control cabinet through a wire. The bus fire extinguishing system has the beneficial effects of being good in fire extinguishing performance, safe, reliable and the like.