Abstract: The Cr3 compound cast steel backup roller was researched as a subject.A backup roller satisfying the required properties was produced by the differential heat treatment process.The temperature distribution of the backup roller in the differential heat treatment process was studied.The hardness and microstructure of the roller's working layer were analyzed.The temperature field of the backup roller in the oil quenching process was simulated by using a developed simulation system of quenching temperature fields.The simulated results were compared with the experimental ones.It is shown that different temperatures in the core and body of the backup roller can be gained by using the differential heat treatment process,and therefore,different microstructures can be obtained in the following oil quenching process.When the backup roller is heated by the differential heat treatment process,the hardness and microstructure of the roller's working layer can meet the usage requirements.The oil quenching process of the backup roller was simulated by using the developed simulation system.The simulated and experimental results are basically consistent,indicating that the simulation system has a higher reliability.The simulation system can be used to optimize the heat treatment process and provides a quantificational reference basis for practical production.