This thesis is entitled "Research on Enterprise Cost Management based on Community Discovery Algorithm", aiming to explore how to optimize the effectiveness and efficiency of enterprise cost management by using community discovery algorithm. In today's competitive business environment, enterprises must continuously improve their cost management level in order to maintain competitive advantage and sustainable development. Traditional cost management methods often rely on manual input data and experience judgment, which is inefficient and easy to produce errors.This study first analyzes the challenges faced by the current enterprise cost management, including complex cost analysis, time-consuming data processing, and inaccurate cost prediction. Then, a cost management model based on community discovery algorithm is proposed. Community Discovery algorithm is a network analysis method that can discover groups of closely related nodes from large-scale data that may represent similar cost items or related business processes in cost management.