Abstract: Aiming at the problems of incomplete combustion and high emissions of rotary engines, a three-dimensional computational fluid dynamics model was established using CONVERGE simulation software. The fuel-air mixture formation, combustion process and emission formation mechanism were thoroughly investigated from three aspects, i.e., compression ratio, volume fraction of hydrogen blending and combustion chamber structure optimization. The results show that hydrogen blending effectively enhances the turbulent intensity of the mixture and reduces hydrocarbon emissions. Increasing the compression ratio improved the combustion process, thereby elevating the thermal efficiency and total work of the engine. Furthermore, the study on the effects of combustion chamber structural modification on the ignition and combustion characteristics of the engine demonstrate that the addition of a bluff body to the rotor pit exhibits remarkable advantages in both mixture combustion and emission formation.