The article uses the large Eddy simulation of Fire Dynamics Simulator（FDS）and parallel computing methods to numerical simulation on fire facilities in an underground garage. The main research is the effects of exhaust system and automatic sprinkler system in fire scene. Results show that: exhaust system can discharge high temperature and toxic gases， reduce smoke concentration and improve visibility effectively. Automatic water spray equipment mainly reduces heat release rate， and make smoke flow near the ceiling， which control the fire temperature very well. Combined with mechanical smoke exhaust system， it can better control the development of fire and effectively put out the initial fire. This study provides reference for fire safety design and assessment， which is of great significance to reduce casualties and property losses caused by the fire of underground garage.