Enterprise Resource Planning system (ERP) provide a comprehensive integrated solution for enterprise informative construction , the practical worker used to think that kind of comprehensive integrated solution already was the optimizes method of the enterprise flow. Therefore, until so far there is no one studying that issue from the perspective of optimized model. For mechanical manufacturing industry (MMI ) characteristics and being combined with practical issues of an enterprise, the paper has proposed the optimized process flow model based on fuzzy nearness from the perspective of optimization for the first time. Performing simulation and optimization to the flow of enterprise's ERP system which uses that model can significantly optimize the logistics relations between different departments of enterprise, increase profitability and also provides methods to decisionmaking and optimization for flow of logistics, meanwhile, it lay the foundation for deep research and design of ERP system.