Based on large area hanging roof in air return roadway and triangle area in transportation roadway in the recovery of fully mechanized working face, hard to collapse, with serious danger, high pressure water cracking coal and rock theory was used to analyze high pressure water injection cracking top coal in fully mechanized working face ends. Based on the hanging roof in Yangcun Mine, high pressure water injection was adopted in working face ends, setting load was reduced by removing anchor bolt and anchor rope firmware, which effectively solved the problem, improved the coal recovery rate, with safe and economic effect.