Abstract: In order to study the influence of process parameters of fully mechanized caving face on top-coal caving ratio, orthogonal experiment design and numerical simulation, the significant size and the optimal range of each of the five factors affecting the recovery of top coal by the range analysis method and variance analysis method. The results show that the influence of each parameter on the smashing degree of top -coal from the largest to the smallest is the mining height, action points of resultant forces, caving step distance, roof control distance, support working resistance, the reasonable parameters of fully mechanized caving face in the mining height of 2.8m; the distance between the action points of resultant forces and the front of the support is between 2.6 and 3.7m, and the larger value should be taken;with two passing cutting and one caving 1.2m step; optimum roof control distance is 4.6~5.2m; and the reasonable working resistance is determined to be 5000 kN.