Abstract: Investigation of a bus fire accident was introduced. By means of on- site inspection, investigation and comprehensive analysis, it is determined that the fire is caused by the leakage of natural gas caused by mechanical fault and electrostatic sparks produced by hitting or electrical circuit short. Starting from the fire investigation, this paper introduces the investigation process of natural gas bus fire, summarizes the experience and experience of handling the case, and plays a guiding role in the management of natural gas vehicle fire. 

Key words: fire investigation, natural gas, bus, mechanical fault