The utility model belongs to the technical field of aircraft cable networks, and particularly relates to a device for rapidly detecting conduction of a high-density jack cable, which comprises an auxiliary pin, a bidirectional connector, a convex head, a rectangular cap pin head seat, a rectangular bottom plate and a pair of steps, the rectangular bottom plate is positioned at the bottom, and the steps are symmetrically arranged on the rectangular bottom plate. The rectangular cap needle head seat is arranged between the steps, the rectangular cap needle head seat is sequentially connected with the two-way connector, the convex head and the auxiliary contact pin, and the auxiliary contact pin corresponds to the round hole, so that the conversion of the detection process is realized, and through the contact between the hole and the needle, the conversion from the needle to the line connection and the conversion from the line to the contact point connection; according to the technical scheme, the identification on the tool corresponds to the corresponding line mark, jack amplification is achieved, highly dense jacks of a cable fixing plate are converted into visual jacks, effective detection of high-density jacks is achieved, and through the conversion mode, operation can be achieved by a single person, and the defect that the detection period of the high-density jacks is long is overcome.