Based on the theoretical analysis of the initial selection of tool parameters, the intrinsic model of stainless steel 0Cr13 material was constructed, and the simplified model was imported into Deform-3D software, and after setting the corresponding parameters, the variation of milling force, milling temperature and tool wear of unequal pitch step plunge milling tool and common plunge milling tool were simulated. Then, according to the fuzzy matter-element theory, a fuzzy matter-element evaluation model was established for the plunge milling tool, and the values of milling force, acceleration and tool wear were measured by milling test, and the milling performance was compared between the unequal pitch step plunge milling tool and the common plunge milling tool by the fuzzy matter-element evaluation method. Milling force, acceleration and tool wear were reduced by 5%, 24% and 15%, respectively. Keyword:plunge milling tool; fuzzy matter-element evaluation method; milling force; acceleration; tool wear proposed to select the optimal combination of angle variations. In China, in 2003, Li Hui et al. [5] proposed the milling force model of single tooth and multi-tooth milling tool and discussed the vibration damping mechanism, and designed and manufactured unequal tooth pitch end mills. In 2011, Li Haibin [6] established an unequal pitch milling force model, found the optimal distribution function, and found the optimal tooth distribution angle. In 2015, Li Xin [7] analysed in detail the vibration suppression mechanism of unequal tooth pitch milling tools, i.e., optimizing the relevant parameters to eliminate the damping term and achieve vibration suppression, and proposed the design index of tooth pitch angle. In 2016, Lu Yanxin [8] obtained that unequally spaced tools can disperse the milling force frequency by frequency domain analysis of the milling force, and then obtained that unequally spaced tools can suppress vibration. In 2021, Nie Wanying et al. [9] proposed that the asymmetric structure of unequal tooth pitch end mills has better cutting stability, the groove parameters were analysed and optimized to improve the balance accuracy, and the relative vibration displacement and cutting force of the optimized tool were reduced by 17% and 10%, respectively, by modal analysis and milling force analysis.With the improvement of automatic processing technology, higher requirements are put forward for tools, and the cutting performance of tools directly affects the quality and efficiency of product processing. At present, the main applied analysis methods are fuzzy evaluation method, finite element method, etc. Among them, fuzzy theory is increasingly used in engineering, and fuzzy evaluation method is very suitable for effective evaluation of objectives under the influence of multiple factors. The method of matter-element analysis was pioneered by our scholar Professor Cai Wen in 1983, which is a discipline between experiment and mathematics. Professor Cai Wen summarized the basic idea of the matter-element analysis m...