The invention aims to provide an aluminum alloy direct current plasma-tungsten electrode argon arc hybrid welding method based on pulse coordination control. A tungsten electrode argon arc welding gun is exerted on one side of a plasma arc welding gun, in the welding process, the tungsten electrode argon arc welding gun is utilized to remove oxidation films on the surface of aluminum alloy in front of the direct current plasma welding gun, and the direct current plasma welding gun is utilized to conduct welding behind the tungsten electrode argon arc welding gun. In order to avoid electromagnetic interference between plasma arcs and tungsten electrode argon arcs in the welding process, when a plasma arc current is in a pulse basic value pilot arc stage, a pulse signal controller is triggered, and a tungsten electrode argon arc current is adjusted to be in a negative half wave crest value for removing the oxidation films on the surface of the aluminum alloy; when the plasma arc current is in a pulse crest value welding stage, the pulse signal controller is utilized to adjust the tungsten electrode argon arc current to be in pulse basic value output, and the steps are repeatedly executed in this way. According to the method, the current pulse wave form of the tungsten electrode argon arcs and the current pulse wave form of a plasma arc power supply are reasonably adjusted, the effect of cleaning the oxidation films on the surface of the aluminum alloy and weld penetration are controlled, and therefore weld formation is guaranteed, tungsten electrode burning losses are reduced, and welding efficiency is improved.