A seat buffering device and a vehicle safety seat including the seat buffering device are provided. The seat buffering device is disposed on a base of the vehicle safety seat. The seat buffering device includes a reinforcing component and at least one concave structure. The reinforcing component is disposed inside the base, and the reinforcing component has a plurality of lateral surfaces. The at least one concave structure is formed on one of the plurality of lateral surfaces. The reinforcing component is adapted to be bent via the at least one concave structure when the base is impacted, so as to reduce impact force applied to the base. Buffering efficiency of the reinforcing component corresponds to the amount, the arrangement, and the angle of the concave structure. The plurality of concave structures is disposed on the same or different lateral surfaces of the reinforcing component in the interlaced arrangement.