Provided is a child safety seat, comprising a seat body and a five-point safety belt disposed on the seat body, wherein the seat body comprises a housing, the five-point safety belt comprises a safety belt buckle, and the housing is internally provided with a storage slot used for storing the safety belt buckle; the seat body further comprises a head support assembly disposed on the housing in a sliding up and down manner, the head support assembly having a predetermined position; when the safety belt buckle is placed in the storage slot, the head support assembly is allowed to be higher than the predetermined position; according to the child safety seat, the five-point safety belt or a car safety belt can be correspondingly selected for use based on the size of a child, and the height of a head support can be adjusted in a corresponding range.