The annealing process is an important part of the metal materials engineering. Processing performance of the material can be changed by heat treatment, give full play to the potential of materials to improve the life of the workpiece. The heat treatment not only for the processing of forging machinery is carried out smoothly and to ensure that processing effects play an important role, and plays an important role in the improvement or elimination of processing defects and improve the life of the workpiece. In this subject,I chose different materials according to the gear conditions of use and performance requirements,and carried on the corresponding heat treatment process design, including the heating temperature, holding time, cooling mode and cooling medium, etc. And through the annealing, coating, such as carburizing, heat treatment, the analysis organization and the change of the performance, on the basis of experiment, verify the correctness of design by heat treatment process. The final conclusion is that, select the 45 steel and Q235 steel as a, 45 steel by annealing and quenching and tempering treatment, Q235 steel by annealing, carburizing, quenching and low tempering. Practice has proved that in order to obtain the desired microstructure and properties, to ensure the quality stability and service life of parts in the production process, from the characteristics of the workpiece, requirements and technical conditions, a careful analysis of the force status of the product during use and mayfailure modes, the correct choice of materials; several possible heat treatment program according to the scale of production, site conditions, the heat treatment equipment, and last based on the stability of its economy, convenience, quality and ease of management, reduce costs and other factors to determine athe best solution.