Abstract: Based on the theory of multi- body dynamics, a dynamical model of drilling boom of crawler roof bolter had been built for the simulation under various wo rking conditions using LMS Virtual. Lab Motion. Then the stress distribution of carriage was obtained through rigid- flexible coupling dynamics simulation, in which the C arriage was taken as a flexible body. The structure of carriage was subsequently optimized. The hydraulic- mechanical coupling simulation implementation was combine d LMS Virtual. Lab AMEsim and the Motion model. The results showed that the pressure and velocity of feeding cylinder were fluctuated within a reasonable range unde r the working conditions and the crawler roof bolterDs drilling boom working status was normal in simulation environment. The simulation could effectively evaluate the dynamic characteristics of drilling boom system, and provid a reference for structure optimization.