The paper aims to explore the reliability of in-situ protective devices under drop impact load. Based on explicit dynamics theory, the finite element method (FEM) was used to simulate the drop impact of in-situ protective devices. The relationship between PCB plate deformation and solder joint failure was analyzed, and the influence of component encapsulation on drop impact resistance of products was discussed. An analytical method for evaluating component encapsulation failure was proposed based on maximum stress on Von Mises and life prediction model. Drop tests were carried out for different encapsulation modes of components. The results show that the simulation results of drop impact of in-situ protective devices were basically consistent with the experimental data. The accuracy of failure analysis method for component encapsulation is verified, providing theoretical support for inferring product reliability.