The invention relates to a multipurpose combination tool for gastight detection, which comprises a multipurpose gas-filled plate, a switch-type charging nozzle, a switch-type gas path pipe joint, a balanced-type rapid fixture and a flexible gas-filled pipe, wherein the switch-type gas path pipe joint comprises a negative conical surface switch-type gas path pipe joint and a positive conical surface switch-type gas path pipe joint; one surface of the multipurpose gas-filled plate is a plane, the other surface thereof is a groove surface, and a first groove and a second groove are arranged on the other surface of the multipurpose gas-filled plate; a penetrating threaded hole is arranged in a central line connection position between the two surfaces; a concave scratch-proof step is respectively arranged on the two surfaces through taking the central line connection position as a center; the switch-type charging nozzle comprises a gas nozzle shell body, a sealing ring, a gas duct switch and a switch rubber piece; the negative conical surface switch-type gas path pipe joint and the positive conical surface switch-type gas path pipe joint comprise pipeline joint shell bodies, sealing washers, gas duct switches and switch rubber pieces; the negative conical surface switch-type gas path pipe joint further comprises an internal thread fastening sleeve and a fastening sleeve limiting ring; the balanced-type rapid fixture comprises a fixture main shell, a balanced press plate and a fixture screw; and the gas-filled pipe is made of flexible plastic.