Abstract: This paper systematically investigates the changes in the microstructure and mechanical properties of 1Cr11Ni2W2MoV martensitic stainless steel under different vacuum carburizing temperatures. The microstructure of the carburized material was analyzed using metallographic microscopy, surface hardness was measured with a Vickers hardness tester, and the hardness gradient of samples after carburizing and quenching under different temperature conditions was evaluated using a microhardness tester. The results show that at a carburizing temperature of 950°C, the microstructure of the sample is uniform, with fewer networked carbides, and the hardness gradient distribution after quenching is more gradual, though the surface hardness is relatively lower. In contrast, at a carburizing temperature of 1000°C, although the carburizing time is shortened, the carburized layer grains become significantly coarser, the amount of networked carbides increases notably, and the hardness gradient shows a sharp decrease, while the surface hardness is higher.