The utility model discloses a cable middle connector protection box. The key points of the cable middle connector protection box are that the cable middle connector protection box comprises two mutually symmetrical semicircular insulated plastic pipes, the connection part of the two insulated plastic pipes is provided with a bolt mounting hole, the two insulated plastic pipes are mutually fixed to be a cylinder through a bolt, two ends of the insulated plastic pipes are provided with mutually symmetrical semicircular cable jacks, one of the insulated plastic pipes is provided with a pressure relief hole with a buckle cover, and a sealing adhesive layer can be filled through the pressure relief hole after the insulated plastic pipes are mutually connected. The cable middle connector protection box has the advantages of simple structure and convenient use, a cable connector can be wrapped in the two mutually symmetrical insulated plastic pipes and is fixed through the bolt, a cable is effectively isolated from the external environment, the sealing adhesive layer can isolate air and the effect of compression resistance is achieved, the sealing effect is good, and the compression resistance performance is strong. According to the cable middle connector protection box, technical problems of simple sealing mode, poor compression resistance performance and poor corrosion resistance effect in the prior art are solved.