The invention discloses a protective sleeve for improving the safety of a wood door, which comprises a plug sleeve which is in a right triangular column shape, a side wall on the plug sleeve, oppositeto the right angle, is provided with an upper and lower corner clamping grooves which are arranged in parallel, the shape of each corner clamping groove is matched with the shape of the plug sleeve,rubber clamping strips are uniformly arranged on the inner side wall of each corner clamping groove, a right triangular support plate, which is arranged in parallel with the corner clamping grooves, is arranged on the side wall of the plug sleeve, between the upper and lower corner clamping grooves, the surface of the right triangular support plate is in flush with the bottom surface of the uppercorner clamping groove, one of the edges of the right triangular support plate, opposite to the right angle, is connected with the plug sleeve, two side walls of the plug sleeve, adjacent to the rightangle, are connected with a sponge plate in parallel, and the sponge plate is connected with the side walls of the plug sleeve through a spring. The anti-collision protective sleeve sleeves on the four corners of the wood door, can greatly improve the protection of the corners of the wood door, and simultaneously plays a role of isolating between two adjacent wooden doors, and is beneficial to the placing and carrying of batches of wood doors.