The infiltration air volume of platform screen doors (PSD) is an important factor affecting the cooling load of subway station. This paper proposes a calculation model of infiltration air volume of PSD. Based on the analysis of test wind speed, the single cycle PSD infiltration air volume is quantified, and the characteristics of infiltration air volume of PSD are studied in different positions and stages. Then, through the analysis of train operation factors, a calculation method of total infiltration air volume of PSD is established, in order to provide reference for the design and operation of subway station. The results show that: （1） the infiltration wind speed of PSD at different positions is different. Along the running direction of the train, the infiltration wind speed and air volume of PSD in a single cycle decrease with the change of door position. The single cycle infiltration air volume of PSD at the exit side is about 65% of that at the entrance side. （2） There are also differences in the infiltration air volume of PSD in different stages. The total infiltration air volume in a single cycle in the train stopping stage is the largest, which is about 10 times that in the train arrival stage. （3） The range of infiltration air volume of single cycle PSD is given, which provides a basis for the calculation of total infiltration air volume, and the corresponding calculation model is proposed, which can calculate the whole day air volume of PSD penetration of subway station.