The invention relates to the technical field of buffering devices, and discloses a safety protection device of a sliding door based on a centrifugal rotation principle. The device comprises a door body, wherein a door frame is fitted at the upper part of the door body; a tension rope is fixedly connected to the bottom of a sliding block; a handle is fixedly connected to the bottom of the tension rope; a buffering box is arranged at a corner of the door frame; a rotating shaft is arranged inside the buffering box; a gear is fixedly connected to the outer side of the rotating shaft; a fixing clamp is rotatably connected to the tooth position of the gear; a fixing block is arranged on the inner wall of the buffering box; and an elastic belt is wound around the outer side of the rotating shaft. According to the safety protection device for the sliding door based on the centrifugal rotation principle, the fixing clamp, the fixing block and the elastic belt are arranged in the buffer box, and the buffer device is stopped when the door body is slowly pushed and pulled by the action of centrifugal force, so that the force during slow pushing and pulling is reduced; and when the door body is pushed and pulled quickly, the buffer device is started, so that accidental clamping injury can be prevented.