The invention discloses a self-tightening type capturing butt joint device and method. The device comprises a self-tightening type capturing butt joint assembly and a driven end, the driven end is arranged on one side of the self-tightening type capturing butt joint assembly, and the self-tightening type capturing butt joint assembly comprises an upper cover plate, floating electric connector sockets, a liquid-circuit making and breaking device free end, a shat hole, a shell, a small gear, a stretching screw rod, a holding-claw bracket, a stretching slab, a holding-claw, a contraction screw rod, a small contraction driving bevel gear, a big contraction driving bevel gear, a contraction shaft sleeve nut, a holding-claw slide shaft, a contraction motor, a stretching motor, a driving gear, anintegral transmission gear ring and a bearing, and the floating electric connector sockets are arranged at the two corresponding ends of one side of the upper cover plate. According to the self-tightening type capturing butt joint device and method, objects of a plurality of specifications can be captured in a self-adaption and contraction mode, the task adaptability degree is high, continuous driving capturing butt joint, blind plugging of an electric connector, plugging and pulling of the liquid-circuit making and breaking device and rigid locking between objects can be achieved, and the device is convenient to use.