In order to effectively prevent fire accidents in chemical enterprises, 24Model is taken to analyze the risk degree of direct causes and clarify the correlation, based on 16 fire accidents occurred in chemical enterprises from 2015 to 2020. The results show that undetected gas concentration (UA₅) and no effective gas detection procedures in place (UA₆) are dangerous with maximum risk R_UA6=0.611. The formation of flammable gases or gases in unsafe physical conditions reaches the explosion limit are dangerous with maximum risk R_UC7=0.626. Additionally, unsafe action trigger path accounts for 82.98% of the total path at most. Unsafe action with the most associated differences is "unstopped illegal operations”, unsafe condition is "residual explosive substance (UC₁) and material compliance (UC₅)". The main point of accident control is to clarify the cause of unsafe action. The research results can be used as the main basis for the prevention of fire accidents and provide theoretical reference for the implementation of targeted control measures.