Explosion-proof diesel engines have undergone significant changes in the new certification implementation rules for emission testing, and various manufacturers have made active responses to this change, and have done a lot of work in source machine selection and commissioning. As an explosion-proof diesel engine testing organization, it is more important to meet the requirements of the new testing standards, while enhancing their own inspection capabilities and testing levels to play an active role in the development of the industry. Finally, the national III emission standard testing system for explosion-proof diesel engines was selected for mines with Siemens power dynamometer, AVL gaseous pollutant sampling and analysis system and CVS full-flow dilution sampling system as the core, the problems of the system and proposed solutions were analyzed.