The Forbidden City in Beijing is the largest and most complete existing palace building in my country. It was initially built in the 18th year of Yongle in the Ming Dynasty (1420). Since then, it has been continuously maintained and rebuilt. It has integrated the palace buildings of all dynasties and has become a model of ancient palace architecture in my country. In the process of building and repairing the Forbidden City, a complete set of palace and ancient building construction techniques with strict forms has been formed. It consists of various craftsmanship such as tiles, wood, soil, stone, paint, color painting, inlay, and mounting. The materials used in the construction are superior, the craftsmanship is rigorous, and the workmanship is fine. The methods and construction procedures of various parts of the palace have strict formulas. It is precisely because of the guarantee of craftsmanship that Chinese palaces represented by the Forbidden City have been able to maintain their luxurious, exquisite, magnificent and brilliant architectural features for hundreds of years. As a model of ancient building construction techniques, official ancient building construction techniques have played an important leading role in the development of ancient building technology in China, especially in the northern region. Since the day of its construction, the Forbidden City has always retained a relatively fixed team to engage in the maintenance and construction of palace buildings. In the early 1950s, the Palace Museum recruited skilled craftsmen from the society to reorganize the ancient building repair team to undertake the maintenance work of the ancient buildings in the Palace Museum. Over the years, this construction team has been serving the Palace Museum. In the process of gradual renewal of members, the traditional official ancient building construction skills have been continuously passed down through the method of oral transmission from master to apprentice.