In order to study the load-bearing law of tungsten carbide ceramic-coated screws in the process of high-strength plastic injection molding, ANSYS finite element simulation was used to calculate the load-bearing characteristics of tungsten carbide-coated screws with different screw ridge structures, and the three-section tungsten carbide coating on steel substrate was analyzed The influence law of screw load, simulates the stress/strain change law of tungsten carbide coated screw under torque load, discusses the corresponding relationship between the load torque of tungsten carbide coated screw and the maximum stress and maximum strain, and establishes the critical torque of tungsten carbide coated screw The method of determination. The results show that the base material and the tungsten carbide coating at the smallest position of the screw bottom diameter bear the maximum stress and the maximum strain. Under the same loading torque condition, the smaller the screw bottom diameter, the greater its bearing stress and strain; Tungsten coating fracture strength/elongation simulation calculation method of critical torque of tungsten carbide coating screw, simulation calculation method of critical torque of tungsten carbide coating screw of unknown steel substrate based on material elastic modulus and yield strength, the calculation results of the two methods are basically verified Consistent; on this basis, the critical torques of the Cr12Mo1V1, 9Cr18MoV, and CPM420V steel base NiMoCrFeCo-WC coated screws are simulated to be 330.34, 346.87, and 363.59N·m, respectively.