The invention discloses a tungsten inert gas shielded welding torch capable of compressing electric arc, and a water cooling heat dissipation device composed of an electrode handle, an electrode seat,a water inlet pipe, a water outlet pipe, an electrode cap and a sealing gasket. The head part of the electrode handle is a tungsten electrode seat for installing tungsten electrodes, a positioning table is arranged on the middle part of the electrode handle, the tail part of the electrode handle is a heat dissipation cylinder, the tungsten electrodes are in interference fit with the tungsten electrode seat, and the tungsten electrodes and the electrode handle are integrated through hard connection, namely a combined electrode. The electrode handle enables the combined electrode and the electrode seat to be accurately connected through the positioning table and the electrode seat. An air passage is formed between a welding torch shell and the electrode seat, a cooling water cavity is formed between the heat dissipation cylinder and the electrode seat, the water inlet pipe and the water outlet pipe are both connected with the cooling water cavity, the water inlet pipe is arranged in thewater outlet pipe, a plurality of guide holes are formed in the peripheral wall of the heat dissipation cylinder, and an opening of the heat dissipation cylinder is opposite to a nozzle of the waterinlet pipe. The tungsten inert gas shielded welding torch capable of compressing the electric arc has good cooling effect, large welding penetration depth, convenient electrode replacement and no influence on the welding effect after each electrode replacement.