Abstract: Taking the NGW type planetary transmission gear in the thin coal seam shearer rocker system as an example, the meshing transmission process is analyzed, the dimensionless normalized meshing curve coordinates are established, and the average contact stress of the tooth surface is calculated and simulated based on hertz contact theory and Ansys finite element software, respectively, and the distribution law of the average contact stress along the mesh coordinates and the finite element stress cloud diagram are obtained, and the correctness and feasibility of hertz contact theory and finite element simulation in solving such problems are verified interactively. At the same time, it also proves the accuracy of 3D model modeling, laying the foundation for subsequent strength verification and transmission optimization design.