Abstract: Coal engineering projects have the characteristics of complex design process and long construction period. Coal design institutes are facing severe problems of transformation and development. The early design stage is extremely important in the whole process of coal engineering construction. It is necessary to improve the quality and quality management ability of coal design institutes. This paper takes the project of Z Coal Design Institute as the research object, analyzes the factors affecting the design results, and analyzes the index factors affecting the design quality from the aspects of human, machine, material, method and environment based on the project quality management theory, method and related standards and norms, combined with the 4M1E method. The analytic hierarchy process is used to construct the hierarchical evaluation model, and the model is evaluated and analyzed, and the countermeasures and suggestions for design quality optimization are put forward, including strengthening design team management, technology construction, strengthening information management and hardware support, and strengthening design quality management system.