Abstract: Fully mechanized long wall top coal caving technology has characteristics as follow: large goaf space, large air leakage, a large amount of remnant coal and easy spontaneous combustion. By eliminating main conditions that cause spontaneous combustion, the method of building waste rock isolation wall in goaf to eliminate fire hazard is put forward, and the fire control effect is investigated. It provides a new fire control technology for the goaf of fully mechanized top coal caving.