Research conclusions: The mechanical ventilation system with open and close operation mode was used for the Dalian subway．The ventilation to the station and sectional tunnel and cooling temperature were achieved by making full use of natural cooling source and the air produced by piston in order to reduce the operation time of the ventilation device as much as possible and save the energy．According to the high air humidity of Dalian in summer，the air pumped into the public area of the station was dehumidified in the hottest months to make the environment more comfortable for passengers．The ventilation system for the station and ventilation system for sectional area equipments were interchangeable． And the operation modes could be switched according to the different conditions to enhance the unilization ratio of the device and reduce the ．first investment and maintenance cost of the device．