Appellation: auxiliary headring auxiliary headring auxiliary headring is a kind of base installed on the gate to hold the knocker. It is a traditional door decoration in China, also called door assistant. Legend has it that the deputy leader is the ninth son of the dragon. He is quiet, alert and good at keeping his mouth shut. The ring held by the auxiliary head is a door knocker, just as the door nail is used to fix the door and the door nail is used to fix the door panel. The knocker is used to open and close doors and knock on doors, so it is a practical object. On the other hand, the auxiliary ring is a common pattern in the portrait stone carvings of the Han Dynasty, which gradually evolved from gluttony. Gluttony is a traditional god beast in China. Because this kind of beast is fierce and greedy, it is usually put on the gate as a shop to exorcise evil spirits. In fact, the paving stones in the Han Dynasty portrait stone carvings often combine the characteristics of many animals, and on this basis, they are exaggerated and deformed. Their shapes are both like cows and tigers, and their faces are ferocious and terrible. On the one hand, it is the embodiment of terror, on the other hand, it is the patron saint. Tiger-headed knockers, which are common in folk houses now, are the continuation of this cultural factor. Civil auxiliary head is generally installed on the main door, with simple shape and round shape, mostly made of iron or copper. When guests visit, they can tap the auxiliary head with the knocker and make a crisp metallic sound. Hearing this, the layman opened the door to welcome guests. The most exquisite is the auxiliary head on the gate of the imperial palace, which is made of copper and plated with gold. Most of these images are tigers, spines, turtles and snakes. The implication of these patterns is that the stars are gatekeepers, which can foretell bad luck, and the lion's head is also used as an auxiliary avatar, which not only means gatekeeper, but also shows the grandeur of royal architecture. China used the auxiliary head as early as the Han Dynasty, and it has been more than two thousand years. The auxiliary header can reflect historical changes and display user status.