For machine tool manufacturing system has the characteristic of diversity, complexity and randomness of dynamic varity in main body of energy consumption structure, ten evaluation indexes are concluded from four aspects including economy, products equipments and task flow, and energy efficiency evaluation index construction of machine tool manufacturing system is structured. In this paper, a combination evaluation method of energy efficiency is proposed. The combination of Rough Sets and AHM is adopted in the step of determining weights, which combines the subjective and objective of weight value. Besides, the gray correlation method and grey fuzzy evaluation are used in other steps, to avoid grey and uncertainty. Lastly, living examples and simulation contrast experiment verify the feasibility and stability of the method.