Abstract: In order to study the influence of mining degree on surface subsidence characteristics under the geological and mining conditions in thick unconsolidated layers, basing the surface movement observation data of 1501 working face of Hongling Coal Mine area, the influence of mining degree on the surface subsidence rate, the tangent of main affecting angle and movement distance of inflection point was analyzed. It was concluded that under the condition of thick loose bed, with the increase of mining degree, surface subsidence rate increases from 0.03 to 0.10, increasing nearly 3 times when the trend mining is shifting from very full mining to not a sufficient mining, and later, with the still increase of mining degree, the surface subsidence rate increases slowly; with the increase of mining degree, the tangent of main affecting angle about the trend decreases more quickly than the tangent of main affecting angle about the inclination direction, and according the geological and mining conditions of Hongling Coal Mine, the experience formula between the mining degree of trend and the surface subsidence rate and the tangent of main affecting angle was fitted out respectively.