According to the surface subsidence problem caused by 10903 workingface of Wanghe coal mine during mining, using program of RFPA2D, the different elastic modulus filling material of backfill mining and all collapse mining were made. It obtained distribution of rupture and frature in caving mining, subsidence curve of the key layer and subsidence curve of surface r in caving mining face advancing. It obtained subsidence curve of the key layer and subsidence curve of surface r in filling mining face advancing of the different elastic modulus filling material of backfill mining.The results show that all collapse mining method cause surface subsidence, but backfill mining method control the key layer bending sinkage and surface subsidence effectively. When the elastic modulus of backfill increase from 1 GPa to 5 GPa, the vertical stress concentration degree in front of the working face decrease gradually, the key layer subsidence also decrease gradually and the maximum sinkage of the key layer reduced from 510 mm to 285 mm. Finally, through the subsidence observation, it is concluded that the proportioning of filling materials and numerical calculation are reasonable.