The evaluation method of a power network is always a hot topic in the power industry. Scientific and reasonable evaluation methods of power grids play an important guiding role in the planning for and reconstruction of a power grid. An evaluation model based on an incentive-punishment mechanism and a variable weight method for the daily operational efficiency of a distribution network is constructed. First, this paper presents an evaluation index system for operational efficiency of a distribution network. Secondly, an incentive-penalty evaluation model and a variable weight theory are used to evaluate the distribution network over a single time section. Then, the operational efficiency of the network over one day is evaluated comprehensively. Finally, the rationality of the evaluation model is verified by an example and a comparative analysis. The result shows that the method proposed can improve the discrimination and sensitivity of the operational efficiency evaluation system and promote the response ability of the evaluation method. This work is supported by the Science and Technology Project of the Headquarters of State Grid Corporation of China (No. SGXJWLOOYJJS1801742) and the Key Research and Development Program of Sichuan Science and Technology Department (No. 2019YFG0152).