Because the new drive device for the crane has an outer rotor structure and is more integrated than the traditional hoisting mechanism, it is easy to cause difficulty in dissipating heat from the stator winding. It is different from the intermittent working system of traditional electrical equipment, which puts forward a new problem for the calculation of temperature rise. According to the characteristics of the equipment, the air cooling structure of hollow shaft is designed. Based on the basic principles of fluid mechanics and heat transfer, a mathematical model of fluidstructure coupling is established. Taking a 90 kW rated power drive device as an example, using the computational fluid dynamics (CFD) software and its embedded userdefined function, according to the mechanism working level and limit operation conditions required by the traditional crane design, programming and simulation are carried out. The temperature rise calculation results are compared with the experimental data under the same conditions to verify the scientificity of the calculation method, and the rationality of the cooling structure is analyzed. The final conclusion provides a reference for the followup research on the heat dissipation of crane drive devices.