Abstract: Taking the vertical ladder pit of Qingdao underground metro station as an example, the temperature and humidity of stations with different buried depths are surveyed, the relationship between buried depth, temperature and humidity as well as the dew point temperature are comparatively analyzed, the causes of dew phenomenon in underground station area are summarized. According to practical experiences, the isolation of contact between cold and hot temperatures and the increase of air circulation will effectively relief the dew condensation. This research provides references for rail transit planning and design.