The utility model relates to a medical negative pressure washing and draining device and belongs to the field of medical instruments. The medical negative pressure washing and draining device comprises a washing part and a negative pressure suction part. The washing part is formed by a washing pipe, a suction pipe cavity and an inflation bag, developing materials are contained in the pipe wall of the washing pipe, a cavity of the inflation bag is located at the lower end of the interior of the suction pipe cavity, and openings communicated with inside and outside are formed among air bags. An opening is contained in the front part of a pipe cavity of the negative pressure suction part, a negative pressure suction pipe is contained in the body part of the pipe cavity of the negative pressure suction part, and the tail part of the pipe cavity of the negative pressure suction part is connected with the negative pressure suction pipe. The body part of the negative pressure suction pipe comprises a plurality of openings and is communicated with outside. The medical negative pressure washing and draining device is reasonable in structural design and convenient to use, the washing part and the negative pressure suction part are integrated, the structure is simple, and manufacturing and popularizing are convenient. The negative pressure suction pipe is in sealing connection with the suction pipe cavity, negative suction efficiency is improved, meanwhile, replacement is convenient, and the probability of infection is lowered; the developing materials facilitate the accurate locating in the pipe replacing process; tissue adhesion can be effectively prevented through the application of the inflation bag, complications are reduced, and the medical negative pressure washing and draining device is worthy of wide application and popularization.