Set up the concrete upturning port around the reserved hole, the concrete upturning port is equipped with a roller track, and a movable cover plate is set on the roller track. When in use, set up the concrete upturning port around the reserved hole, install the roller track above the upturning port, and finally rest the cover plate with the track, and move the cover plate along the rolling direction of the roller; at the same time, the top of the cover plate is covered with light-transmitting toughened glass, which is not only rain-proof but also allows the light to pass through.