Eating fish in the new year means that there is more than one year. The homophonic word "surplus" of fish not only represents surplus, but also symbolizes the elimination of monsters. In the ancient Han dynasty, the fish painted on the door played a very important role in demon suppression. In the Tang Dynasty, fish patterns appeared on doorknobs, doors, cupboard doors and box doors to exorcise ghosts. Therefore, the concept of designing fish with doorknobs has a great influence on China people's eating fish in the New Year. Demons and ghosts are slowly forgotten. At the same time, it is a feudal saying that the fish as the last course is not eaten clean.