Abstract: This article investigates the effect of pulse laser welding speed on the microstructure and mechanical properties of DC06 ultra deep drawing steel plate welds.The results of metallographic and hardness experiments show that as the welding speed increases,the welding heat input decreases,the cooling speed increases,and the ferrite grains in the weld and heat affected zone decrease;At the same time,the welding speed increases,the high-temperature residence time is shortened,the burning loss of alloy elements is reduced,the solid solution strengthening effect of the weld and heat affected zone is enhanced,and the microhardness is increased.