Abstract: In order to realise the green manufacturing of CNC machining system, a CNC machining parameter optimisation method oriented to low energy consumption and high quality is proposed. Firstly, the energy consumption characteristics of the CNC machining system and its subsystems under different operating conditions are analysed; then, with low energy consumption and low surface roughness as the objectives, the milling speed and feed amount are selected as the variables, a multi-objective optimisation model of the milling machining system is established, and the NSGA-II genetic algorithm is employed to solve the proposed model, then the most suitable machining parameters are decided from the equivalent solutions using the Topsis method. Finally, the validity of the proposed approach is verified with a cylinder stator endface machining case, and the feasibility of the optimisation model is further illustrated by the analysis of the results.