In the operation of refrigeration systems, the compressor is the main electrical equipment to achieve the refrigeration cycle. Compressor energy consumption accounts for the major part of the energy consumption of the whole refrigeration system operation. Compressor energy consumption is proportional to the input power and running time. For the open compressor with motor input power is 1.1–1.5 times the shaft power. The shaft power is a prerequisite for the determination of compressor energy consumption analysis. The purpose of this paper is to use the least squares method to fit the compressor cooling capacity, shaft power performance curve to derive a certain condensing temperature, different evaporating temperature compressor cooling capacity, shaft power continuous function curve and function expressions, while double-position adjustment automatic control system running time, and finally determine the compressor energy consumption mathematical model.