Abstract: Fire accidents occur frequently in the operation of railway large maintenance machinery ,which seriously affects the safety of railway transportation. Aiming at the hidden dangers of fire hawards in rail-way large maintenance machinery engine，measures such as isolation of heat source and danger source,fire alarm monitoring，and fixed fire extinguishing equipment are taken. The experiment of installation shows that the measures can effectively prevent fire in railway large maintenance machinery engine. 

Key words: large mainlenance machinery of railway;engine;fire alarm monitoring, fixed fire extin-guishing equipment