Abstract: For the problem of low top-coal release rate, a large quantity of coal dust in the process of top coal caving mining in three-soft and unstable thick coal seam, through the analysis of the influence factors of top coal caving, we proposed a complete set of optimization measures for top coal caving technology. First, we accurately detect the thickness variation of local seam at working face, and then use high level drilling water injection to solidify and loose coal; finally, we optimize the caving technology in a reasonable manner. Results show that optimized caving technology makes top coal's recovery ratio improved by 10.5%; coal seam water injection not only improves the adhesion of coal, coal dust amount of each process has been also significantly decreased, and average drop is 63.44% and the largest decline is 68.14%, which realizes the caving under the condition of the three soft coal seam with high efficiency and low dust and obtain significant technical and economic benefit.