Abstract: The effects of different cooling rates on the microstructure and property of 25CrNi2MoV bearing steel were studied by Gleeble-3500 thermal simulation machine, OM, hardness test and wear test. The results show that the microstructure of 25CrNi2MoV steel is mainly bainite + ferrite when the cooling rate is between 0.2 and 3.0 ℃/s. With the increase of cooling rate, the ferrite content gradually reduces and the grain is gradually refined, and the hardness values are all below 250 HV and the wear resistance is poor.When the cooling rate is 10 ℃/s, the microstructure of 25CrNi2MoV steel is a mixture of martensite and a small amount of bainite.When the cooling rate reaches 30 ℃/s, residual austenite begins to form in the microstructure.The hardness of 25CrNi2MoV steel is above 430 HV and the wear resistance is good when the cooling rate is in the range of 10-60 ℃/s.