The article analyzed the working principle of the injection molding machine and energy consumption, and researched the key energy saving technologies.By contrasting, energy saving transformation models for oil pump system of injection molding machine motors and heating system energy consumption were built up, and then it drew the energy saving rate prediction method based on the models.The feasibility is verified through examples, which provides the theory basis for the energy saving reform of the injection molding machine and energy saving rate prediction, provides algorithm supports for modification effect economic evaluation.