The work aims to establish a numerical analysis model of coated materials with particle defects under the linear load, so as to explore the effects of particle defects on the contact mechanical performances of coated materials, and provide theoretical guidance for the optimization design of coating technology for mechanical transmission parts in engineering. Semi-analytical method (SAM) was employed to construct a linear contact model for heterogeneous coated materials containing particle defects and the calculated results were in good agreement with those obtained by the finite element method. Based on the model, the effects of friction coefficients and the locations and distributions of particle defects on the value and depth of maximum von Mises stress in coated materials containing particle defects were studied. The maximum von Mises stress went up, and the depth positions exhibited step changes from near matrix-coating interface to the coating surface, with the increase of the friction coefficient. When the x-coordinate of the particle defect center changed from left to right, the maximum von Mises stress increased and then decreased, the corresponding depth positions were located near the matrix-coating interface or the upper surface of the particle defect. With the increasing distance between the particle defect and the coating surface, the maximum von Mises stress increased, then decreased, and became stable, and the depth position went away from the coating surface and then stayed in the coating area or the matrix-coating interface area. The effects of the randomly distributed particle defects on the maximum von Mises stress were complicated, and the depth positions were located near the matrix-coating interface or the interface between the matrix and particle defects. Friction coefficient and locations and distributions of particle defects can greatly affect the contact mechanical performances of the coated materials containing particle defects under a linear load.