The invention discloses a wire harness plug-in. The wire harness plug-in comprises an outer shell, a male terminal assembly and a female terminal assembly, wherein an axial containing cavity is formedin the outer shell, and a first opening and a second opening are formed in the two terminals of the axial containing cavity respectively. The male terminal assembly comprises a first core body and amale terminal, a first through hole is formed in the first core body, and the male terminal penetrates through the first through hole. The two terminals of the male terminal are exposed out of the outer side of the first core body. The female terminal assembly comprises a second core body and a female terminal, and a second through hole is formed in the first core body, the female terminal penetrates through the second through hole, and one terminal of the female terminal is exposed out of the outer side of the second core body. The first core body and the second core body are respectively inserted into the axial containing cavity from the first opening and the second opening, and the male terminal extends into the second through hole and is in butt joint with the female terminal. According to the invention, the male terminal assembly and the female terminal assembly are arranged to be basically the same in structure, and the male terminal assembly and the female terminal assembly areinserted into the outer shell. The universality of the wire harness plug-in is improved, and the cost is saved.