Abstract: The microalloyed steel was used as the original sample, the test samples were prepared by different heat treatment. The microstructure was observed by metallographic microscope and scanning electron microscope, and the hardness and strength were studied by Rockwell hardness tester and tensile tester. The results show that, when the quenching temperature of the microalloyed steel is 850 ℃ and the tempering temperature is 400 ℃, the microstructure obtained is tempering troostite. At this point, the strength and plastic toughness of the microalloyed steel are well matched.