ABSTRACT In the process of lightweight design, there will be problems such as stress concentration and structural weakening. In order to improve the design defect of serious insufficient life caused by the bending failure of worm gear, the bending stress of worm gear tooth root was analyzed by solution method and finite element simulation method. The main research contents include: firstly, the bending stress of worm gear is calculated by analytical solution method; Secondly, CAD is used to reconstruct the model; Finally, HyperMesh is used for analysis of the structure. The maximum bending stress obtained from theoretical calculation is 34.56Mpa, and the maximum stress from simulation is 39.3Mpa, 29.6Mpa and 26.3Mpa respectively in the three areas of gear root A, B and C (figure 7). Compared with the finite element, the maximum stress difference between them is 4.74Mpa. The stress concentration point is determined, and the structure optimization is carried out; CAE analysis of the optimized model shows that stresses in A, B and C regions of the worm gear root are 33.4 MPa, 22.5 MPa and 5.9 MPa, respectively. After optimization, the maximum stress difference between the two is 1.16Mpa.The above analysis results provide theoretical support for the design of worm gear reducer.