Abstract: The nonlinear dynamic characteristics of wedge lock used in the electronic equipment are studied in this paper．By analysis of load vs displacement status，a simplified nonlinear dynamic model is established which can reveal the nonlinear dynamic characteristics of the wedge lock．The nonlinearity is modeled by nonlinear spring elements with different tensile and compressive stiffness．The numerical simulation is done based on this dynamic model and is compared with the test result.The result shows that this connecting model is reasonable and it is the wedge lock that makes the whole system have strong nonlinear dynamic characteristics．