The present invention discloses a cylinder head thermal shock test bench based on pre-tightening force, and a method thereof. The test bench comprises a test apparatus and a control system, wherein the test apparatus comprises a cylinder head requiring detection, bolts, a valve mechanism, infrared heaters, an insulation pad, a cylinder gasket, a sense heating coil, a pseudo body, a fixing table stand, a sense heater control system, an infrared heater control system, a water pump, a water tank, a heater, a thermostat, and the like. The cylinder head requiring detection is additionally provided with the valve mechanism. The cylinder head requiring detection, the insulation pad, the cylinder gasket and the pseudo body are sequentially connected, and are fixed with the bolts. The front side and the rear side of the cylinder head requiring detection are provided with the infrared heaters. The sense heating coil is arranged inside the pseudo body. The cylinder head requiring detection is connected with the water tank through a water pipe and is driven by the water pump. Forced water cooling is performed on the cylinder head requiring detection. The test apparatus is controlled by the control system. With the present invention, the pre-tightening force is considered as the mechanical constraint, such that the actual working conditions can be simulated realistically, and the thermal fatigue state and the thermal shock state of the cylinder head can be accurately analyzed so as to improve the credibility of the test results.