Abstract: The butt welding tests of 3.5 mm thick BR1500HS high-strength steel plate were carried out by using fiber laser wire-filling welding and mixed gas shielded welding with ER70-G welding wire, respectively. The samples were heated to 900℃and held for 5 min, then quenched in water. The tensile test and hardness test of the welded joints before and after quenching were carried out, and the macroscopic morphology and microstructure of the welds were studied. Field emission scanning electron microscope was used to analyze the fracture morphology of the welded joint.The results show that the joint strength of the two welding methods before quenching exceeds the base metal strength, and the strength of laser welded joint after quenching is significantly higher than that of gas shielded welding with the maximum of 1805 MPa.Before quenching, a large amount of martensite and a small amount of bainite are generated in the weld zone and heat-affected zone of laser welding, and the microhardness reaches 430HV. While the microstructure of the weld zone and heat-affected zone of gas shielded welding mainly consists of bainite, pearlite and a part of ferrite, and the microhardness is only 380 HV. After quenching, the weld zone and heat-affected zone microstructure of the two welding methods are both martensite and residual austenite, but the martensite content of the laser welding joint is higher and the microhardness of the weld zone is higher. After quenching, the fracture of gas shielded welding joint is plastic dimple fracture, and the fracture of the laser welding joint is quasi-cleavage fracture. The strength of gas shielded welding joint is lower but the plasticity is better.