Along with increasingly become serious problem of energy crisis and environment pollution in todays society, the Green manufacturing technology seems particularly important. Moreover the choice of cutting speed in manufacturing is a key to Green manufacturing. However, the traditional choice of cutting speed was often to rely on the working experience or consulting the manual, which was not able to meet the requirements of Green manufacturing obviously. In order to choose the more reasonable cutting speed, a cutting speed optimization mathematical model was set up, whose index included processing time，costing of production，energy consumption and tool service life, and etc. Then a method combined AHP with Grey Relation Analysis Method was used to solve the mathematical model. In this way, choice of cutting speed is more effective and exact.