Abstract: The different test schemes were designed, the 40Mn steel strip was quenched with 10% PAG and air as the quenching medium.The quenched steel strip and the unquenched steel strip were subjected to tensile test and hardness test, and the metallographic structure of the steel strip was observed using a metallurgical microscope.By data comparison, it is found that when the quenching temperature is 840 ℃the 40Mm steel strip with air as the quenching medium has the best performance.The tensile strength is 752.5 MPa, the hardness is 289.3 HV0.2, and the metallographic microstructure is fine.The microtissue is small pearads and ferrite.By using PAG as the quenching medium, when the quenching temperature is 840℃, the 40Mn steel strip has the best performance, the tensile strength is 1682.9 MPa, the hardness is 623.8 HV0.2, and the microstructure is mainly martensite and a small amount of retained austenite.Comparing the sample parameters obtained after quenching by air and PAG quenching liquid with the parameters of the raw material sample, it can be obtained: after air quenching, the performance of the sample is slightly improved, and after quenching with 10% PAG quenching liquid, the performance of the sample is significant promoted.