This paper analyzed the investigation process of a fire in a liquor workshop which belongs to the situation of the civil buildings transformed into productive buildings. The report emphatically illustrated how investigators had determined the cause under circumstances of the interest between witnesses, the inconsistency in testimony, the difficulty of field- trace analysis, and the absence of critical trace evidence. The videosurvey technique was implemented to make a breakthrough. The angle of light was measured to determine the ignition spot. Simulation tests were conducted to invert the origin of the fire, and similar equipment was investigated to improve the evidence chain. Eventually, the cause of the fire was accurately determined. The investigation process makes an in-depth analysis of the inducing factors, forming origin and spreading reasons for this kind of fire, and provides clear ideas and suggestions for a similar case.

fire investigation, video- survey technique, simulation test