Polydactyly accounts for a very high percentage of congenital hand and foot deformities and is arguably one of the most common hand deformities. It can be polydactyly of one hand or multiple fingers, with rounded polydactyly being more common. The cause of its development is unclear and may be related to the physical state of both parents during preparation for pregnancy, the health of the mother during pregnancy, as well as the external environment and genetic factors. Genetic factors refer to the fact that there is a precedent of polydactyly in the family of both parents, which leads to the birth of a baby with polydactyly. However, this is a matter of chance, and it does not mean that if there is a precedent of polydactyly in the family, the child will definitely have polydactyly. Parents do not need to worry too much if their child is born with polydactyly, as this can be corrected by surgery later in life. Polydactyly surgery is a test of the anatomical knowledge and experience of the surgeon in charge, if the operation is not careful, it may lead to the subsequent “growth” of the situation, so parents must be careful when choosing a doctor.