Abstract: The wooden arch covered bridge is a bridge style that originated in the Northern Song Dynasty. Due to the particularity of its structure, in the years of exposure to the sun and rain, the wood is corroded, carbonized and loosened, and the fire risk is constantly increasing. Through on-site inspection and evidence collection, video image analysis and simulation restoration experiments of a wooden arch covered bridge fire, this paper analyzes the entire process of the wooden arch covered bridge from smoldering to ignition and disaster, finds out the cause of the fire accident, and puts forward corresponding preventive countermeasures and suggestions, providing reference for the investigation and determination of fire accidents in cultural relics and ancient buildings.

Key words: wooden arch covered bridge, fire investigation, cultural relics and ancient buildings