Abstract: The continuous cooling transformation(CCT) curve of a novel Nb-V microalloy strengthened wear-resistant liner steel was determined through the thermal expansion experiment. The microstructure and hardness variation laws of the steel under different cooling rates were systematically studied by using field emission scanning electron microscopy and Vickers hardness tester. The results show that when the cooling rate varies within the range of 0.01 ℃/s to 20 ℃/s, the steel undergoes three types of phase transitions, namely pearlite, bainite and martensite in sequence with the increase of the cooling rate. When the cooling rate is lower than 0.05 ℃/s, the main product of the phase transition is pearlite with a low hardness. When the cooling rate is 0.1 ℃/s - 0.5 ℃/s, the microstructure is a bainite-martensite composite structure, and the hardness gradually increases. When the cooling rate exceeds 0.5 ℃/s, a complete martensite microstructure can be obtained, with a hardness up to 650 HV. Holding at 880 ℃ for 20 min and cooling at a rate exceeding 0.4 ℃/s can obtain a single martensite microstructure or a martensite-bainite duplex microstructure, which can significantly increase the hardness of the new wear-resistant liner steel, thereby improving the impact abrasive wear resistance under low impact load conditions.