As more and more people across the world adopt subways as their primary mode of transportation,the energy consumption has become very quick.This paper performed an experiment,which is aimed at this serious problem of energy waste caused by normal close of return air damper of ventilation system for metro cars,to control constant static pressure of return air damper and to verified this strategy of energy saving control through Fluent simulation.The results show that this method can save energy effectively on the premise of ensuring the comfort of passengers.