Reserved opening structure and construction method thereof

The invention relates to a reserved opening structure which comprises a frame body for being fixed to a reinforcement cage of a main body structure, and after the main body structure is formed, an opening is formed in the frame body; and the door plate is rotationally mounted on the frame body, and the opening is blocked or opened by rotating the door plate. The problem that time and labor are wasted when formworks are frequently erected is effectively solved, a reserved opening structure is provided, the reserved opening structure is opened when the cantilever steel component is installed and closed after the cantilever steel component is dismantled, frequent formwork erecting is avoided, time and labor are saved, construction efficiency is improved, construction quality is guaranteed, and the structure is simple, convenient to achieve and low in cost. The method has good adaptability and economic benefits. 本发明涉及一种预留口结构，包括：供固定于主体结构的钢筋笼的框体，待形成主体结构后，框体的内部形成有开口；以及转动安装于框体的门板，通过转动门板以封堵或敞开该开口。本发明有效的解决了频繁支设模板费时费力的问