Through orthogonal numerical experiments, the significance of the effect of four thermal environmental parameters on PMV was compared, which indicates that the degree of the influence of four thermal environmental parameters on PMV in descending order is air temperature, indoor wind velocity, mean radiant temperature and relative humidity within the usual range. Furthermore, the influencing laws and the significance of the effect of the four environmental parameters on energy consumption under PMV control were analysed. Under the premise that PMV remains unchanged, the energy consumption of different combinations of thermal environment parameters were compared. It is found that there is a huge difference between different combinations on energy consumption, which indicates the presence of an optimal combination consumes the minimum energy while satisfying human thermal comfort. The above analysis provides directions and basis for the further study of PMV optimal control of air-conditioning systems.