Shenyang No.1 line was measured in order to know about the subway tunnel thermal envi. ronment in cold winter.A typical underground tunnel, a tunnel between ground and underground and a typical station were picked as the test content.Test was measured by self—recording instruments to record parameters when train was running.The measurement results show that there exists a high syn—ehronism between the entrance of the tunnel temperature and the outside temperature.Reasonable use of high—power air curtain can effectively improve tunnel temperature in a short time, and it will en—sure the tunnel temperature will stay above zero from the first station, which could make the fire pro—tection system avoid freezing without insulating course.The heat produced by train and platform have an intermittent influence on tunnel temperature by piston effects with the piston shaft off.And the air temperature fluctuates in the range of 1 degree Celsius, which always lower than the heating temperature in station.So this energy will not be able to use by the ventilation and air condition system of sta—tion.It is suggested here that using an adjustable ventilation platform doors and realizing its shielding function in winter will be an effective way to prevent energy dissipation.