Because of the lack of effective quantitative benefit evaluation methods for applying digital enterprise resource planning systems in supply chain management, this paper proposes a supply chain management benefit evaluation method after implementing the ERP system. This method starts from the two aspects of ERP implementation cost and quantitative income, establishes the evaluation index system of supply chain management benefit, then normalizes each index, uses the Delphi method to determine the weight of each quantitative income, constructs the evaluation model of enterprise supply chain management benefit after ERP implementation, and finally obtains the evaluation score in the form of the ratio of quantitative income to ERP implementation cost. In order to verify the feasibility of the model, the data of CM company from 2015 to 2022 are selected for simulation experiments. The calculated benefit evaluation score is consistent with the actual situation of the company's operation. Therefore, the model can effectively evaluate the benefits of applying digital enterprise resource planning system in supply chain management and provide strong support for enterprise management to plan ERP implementation and follow-up maintenance decision-making.