The invention discloses a bench test system and test method for an air conditioner cutting condition and a whole vehicle braking condition. The bench test system comprises a host computer, a data acquisition device, an environment simulation cabin, a chassis dynamometer, a test vehicle and also comprises an engine outlet water temperature sensor, an engine inlet water temperature sensor, an engine oil temperature sensor, an air conditioner blowing surface air outlet air temperature sensor, a compressor air discharge pressure sensor, a compressor air suction pressure sensor, a cooling fan voltage sensor and a compressor clutch voltage sensor which are electrically connected to the data acquisition device. The host computer is electrically connected to the data acquisition device and an ECU of the test vehicle. The test method comprises the steps of carrying out test vehicle access inspection, laying each sensor and connecting wires, fixing the test vehicle and connecting wires, setting a simulation environment, preheating the test vehicle, simulating the breaking condition to drive and collecting data, and recording and analyzing the data. According to the system and the method, the test universality and the comparability of a test result can be improved.