Abstract: Objective The purpose was to study forming regularity of backing weld and covering weld under different welding parameters and explore optimal welding parameters for backing layer and covering layer. Methods Taking titanium alloy (TC4LCA) plate with 10 mm thickness as base material, laser-arc hybrid welding process was used for backing welding and covering welding, and macroscopic morphology analysis and mechanical performance test was carried out on welded joints. Results The results showed that under the conditions of 60° Y-shaped groove, 4 mm blunt edge thickness, 4 mm spacing between laser and wire, 3.0 kW laser power, 1 m/min welding speed and 150 A MIG arc current, a well formed backing weld could be obtained. Under the conditions of 1.0 kW laser power, 0.6 m/min welding speed and 200 A MIG arc current, a well formed covering weld could be obtained by filling twice. No cracks, porosity, slag inclusion or other defects were found in welded joints. Conclusion Strength of welded joints obtained by laser-MIG hybrid welding method was high, reaching 97.8% that of base metal.