Firstly, the necessity of adding a refrigeration system to a helicopter is described. It is considered that the vapor cycle refrigeration system is the development trend of the future airborne refrigeration system. Taking the AC313 helicopter as the research object, this paper using Airpak software and kepsilon double equation turbulence model, the simulation results of cabin temperature field, velocity field, PMV-PPD and air age distribution are obtained. The comparison and analysis of the simulation results of the two schemes show that the side air supply is more comfortable for passenger than the downward air supply under the same condition.