Abstract: Orthogonal test method was used to optimize heat treatment process of the heat-resistant steel ZG1Cr10MoWVNbN for ultra supercritical steam turbine.The influences of three factors,i.e.normalizing temperature holding times and tempering temperature,on structures and properties of the heat-resistant steel were analyzed.The results show that optimum properties of the steel are obtained which normalized at 1 000 ℃ for 5 h,tempered at 670℃ for 5 h and cooled in furnace,then cooled in atmosphere from 300 ℃ to room temperature.