The hea-ttreat process,microstructure and properties of Al-V microalloy high-strength steel was studied by means of mechanical property test,OA and SEM analysis in the laboratory.The results show that the density of the test steel added 3%Al is 7.515 g/cm3,and the weight of the steel plate with identical specification can be reduced by more than 4%,the properties of the test steel by 900℃ quenching and 540℃ tempering can meet the technical requirement of ReL≥460 MPa,Rm≥630 MPa,A≥18%,-20℃ KV2≥80 J,the microstructure is tempered sorbite,with excellent strength and toughness match.