Abstract: The dual-torch laser-MIG hybrid welding process of 20 mm thick TC4 ELI titanium alloy plate was investigated, and the welded joint of 20 mm thick TC4 ELI plate was fabricated. The microstructure, mechanical properties and process performance of the welded joint were systematically studied. The results indicate that the dual-torch laser-MIG hybrid welding can produce TC4 ELI titanium alloy welded joint that meet the standard Grade I requirement. The microstructure of the weld zone consists of needle-like martensitic α' phase, needle-like α phase, and a small amount of intergranular β phase. In the upper heat-affected zone(HAZ), continuous, well-defined grain boundaries and Widmanstätten structures are observed.The middle HAZ exhibits unclear grain boundaries, with refined microstructures; the β-phase transformation structures are elongated to finer needle-like α phases, which aligns parallel to the β grain boundaries, forming α bundles. In the upper fusion line, coarse α phases and stable basketweave structures are present, while in the middle fusion line, the needle-like α phases exhibits a high aspect ratio, resulting in a narrower basketweave pattern. The average tensile strength of the joint in the upper and middle regions is higher than that of the base material. The hardness of the weld zone in the backing layer and filler layer is also bigger than that of the base material and HAZ. The bending performance of the joint is qualified, and the overall process performance is acceptable.