The types of low alloy high strength steel can be divided into non-quenched and tempered steel. Generally non-quenched and tempered steel refers to steel with tensile strength below 600 MPa at room temperature, and quenched and tempered steel is manufactured by machinery, pressure vessels and submarines; yield strength of 880 ~ 1176 MPa is mainly medium carbon quenched and tempered steel, which is often used for high strength Product or component, connectivity, on a bridge. Reference studied the effect of welding heat input on the HAZ toughness and microstructure of quenched and tempered HQ130 steel (yield strength 1313MPa). The test results show that as the welding heat input increases from 9.2kJ / cm to 26.4kJ / cm, HQ130 The impact toughness of steel HAZ gradually decreases, so it is widely used in the fields of security, construction, ships, high-pressure vessels, engineering machinery and vehicles. The low-alloy quenched and tempered high-strength steel has a relatively stable structure under any complex conditions such as repeated heating, deformation, and cooling, and has a good guarantee for the ultimate performance of the steel plate. Quenched and tempered high-strength steel has both high strength and plastic toughness . Due to its excellent performance and significant economic benefits, quenched and tempered steels are increasingly used in engineering welded structures. How to obtain quenched and tempered steel welded structural parts with excellent performance has always been the research focus of researchers.