In order to speed up the research and development progress of pneumatic monorail crane and make full use of the high efficiency and convenience of computer aided design, solidworks software is used to carry out three-dimensional modeling, motion simulation, static analysis and optimization design of the gear transmission part of pneumatic monorail crane. According to the principle of mechanical design, the size of the gear is calculated. On this basis, the three-dimensional model of the gear is established. In Solidworks / Motion software, the motion simulation test of the large and small gears is carried out, and the force curve of the gear meshing tooth surface is obtained. The static analysis of the gear is carried out in Solidworks / Simulation software, and the stress cloud diagram of the wheel set after loading is obtained, and the stress distribution of the whole gear is analyzed. According to the stress distribution of the gear, the gear is optimized, the stress concentration is reduced, and the weight is reduced by 41 %, which achieves a better lightweight design effect.