The utility model discloses a remaining needle waterproof jacket which comprises a waterproof jacket body. An arm is sleeved with the waterproof jacket body. Elastic bands are arranged at the two ends of the waterproof jacket body. Water absorbing mats are detachably mounted at the positions, close to the elastic bands, of the inner wall of the waterproof jacket body, and the water absorbing mats seal gaps between the arm and the two ends of the waterproof jacket body. Besides the cylindrical waterproof jacket body, the water absorbing mats are additionally arranged at the positions close to the two ends, and a hard protection hood is arranged inside to protect a remaining needle; a vacuum valve is arranged to control the vacuum degree inside the waterproof jacket body. A patient can feel comfortable, water can be effectively prevented from entering the jacket and reaching the remaining needle, and a good antibacterial effect can be achieved. In addition, the waterproof jacket can be used for skin with wounds, skin ruptures and the like to prevent the skin from being wetted, infection and complications caused by skin wetting are avoided, the infection probability of the patient is lowered, and life quality is improved.