In 1994, the crossbow machine was excavated from Wanquhou tomb in Bojishan. The upper part of it has a cover. There is an arrow slot in the middle of the outline and a horizontal hole in the front and back of the side respectively. The Xuandao, Wangshan and hook were connected by keys. The front key is made of wood, the back key is made of iron, and the hook and Xuandao are bonded due to corrosion. The log arm has been lost, leaving traces of rotten wood on the cover. There are gold inlaid cirrus cloud patterns on the cover, Wangshan and Xuandao.