Electric gate of Huisman Iron and Steel Products Factory is the largest multi-stage lift gate in China. The door body is 43.2 meters wide, 28.2 meters high, and weighs 100 tons. This door is an extra-large multi-stage lift door, which breaks through the traditional structure of small and medium-sized multi-stage basket doors and solves the problem of installing multi-stage lift doors at ultra-wide and high-height openings Technical difficulties. The door is an upper and lower containment structure, which is divided into six sections. When the door is closed, it engages up and down. When it opens, it nests with each other. The door can maintain the overall strength, stiffness and stability in all positions and directions. In the lower part of the door, there is a daily freight passage with a width of 4 meters and a height of 4 meters, which facilitates the passage of personnel and minivans when the door is closed.