A model of five layers of fuzzy neural network which is appropriate for high-speed machining (HSM) processing optimization is proposed to fully exert the advantages of HSM. This model built a mapping relationship among the credibility of three-optimization objective "efficiency priority", "quality priority" and "precision priority”, material removal rate, cutter rigidity, machine-tool precision, and the smooth degree and fitting error of tool path. Gradient descent method is used to conduct training of network on the basis of orthogonal test. The constraints are also given in the HSM processing optimization objective. A prototype system of HSM processing optimization is developed based on fuzzy neural network. The result of test shows that not only the systems runs reliably and steady, but also the processing scheme optimized is economic and reasonable.