Overview of screen doors Screen doors (also known as platform screen doors or security doors, English: Platform screen doors(PSD) or Platform-edge doors) refer to the glass curtain walls around the railway platform and the train boarding and alighting space on the platform. When the train arrives at the station, open the electric door on the glass curtain wall for passengers to get on and off. The subway screen door system is a device installed on the side of the subway platform near the track to separate the platform area from the track area. In the first phase of Shenzhen Metro, screen door systems were installed at all stations along the line. The main purpose of installing the screen door system is to prevent people from falling off the track and causing accidents, reduce the operating energy consumption of the station air conditioning and ventilation system, reduce the impact of train noise and piston wind on the station, provide a safe and comfortable waiting environment for passengers, and improve the service level of the subway. 2 Type of screen door system 1, fully enclosed screen door It is a top-down tempered glass partition and movable door, which is arranged along the edge and both ends of the station platform and can completely isolate the waiting area of the platform from the train parking area. The main functions of this screen door system are to increase safety, save energy consumption and reduce noise.