Abstract: In view of the lack of relevant evaluation methods for the reliability of coal mine electrome⁃ chanical system in the process of deep mining in coal mines，13 influencing factors were selected from the perspectives of human，machine and environment，and the feedback relationship between each factor and the reliability of coal mine electromechanical system is clarified. The reliability evaluation system is con⁃ structed. Based on the extension theory，the calculation method of objective correlation degree of reliability evaluation index of coal mine electromechanical system is given. Based on the improved fuzzy analytic hier⁃ archy process，the subjective weight calculation method of each index is given. Finally，a reliability evalu⁃ ation method of coal mine electromechanical system based on improved fuzzy analytic hierarchy process�extension theory is proposed. The results show that the improved fuzzy analytic hierarchy process and the evaluation method of extension theory，from the subjective and objective point of view of comprehensive evaluation，the effect is more realistic. The main factors affecting the reliability of coal mine electrome⁃ chanical system are the execution rate of maintenance cycle，the response time of emergency plan，the overall rated residual life grade of equipment and the average material performance qualification rate. The reliability of coal mine electromechanical system can be greatly improved by improving the relevant indica⁃ tors. Finally the reliability evaluation grade of the electromechanical system of the coal mine is obtained by field application，which proves that the method has high feasibility，and the targeted improvement mea⁃ sures have a guiding role in improving the reliability of the electromechanical system of the coal mine，and improve the comprehensive benefits of the enterprise.

Key words: coal mine electromechanical system, improved fuzzy analytic hierarchy process, exten? sion theory