Abstract: In order to study the effect of deep complex orebody mining on the stability of surface buildings， the probability integral method was used to calculate the safe mining depth. The 3D Mine-Rhinoceros-FLAC^3D coupling method was used to construct a refined 3D model of mining area to study the surface safety and deformation characteristics. The results are as follows: when deep ore body mining is carried out by filling method， uniform settlement deformation occurs on the surface; the maximum principal stress increases polynomially with the increase of mining steps， the minimum principal stress increases linearly， and the disturbance height presents a normal distribution trend along the ore body; the mining of ore body causes ‘basin deformation’ over the ore body， and disturbance boundary is delineated according to surface safety parameters; when the subsidence deformation value is less than 10mm and the change rate is greater than 0.5， or when the subsidence deformation value is greater than 10mm but less than 20mm and the change rate is greater than 1.5， the whole surface subsidence is negligible.

Key words: three-underground mining; safety mining depth; 3D Mine-Rhinoceros-FLAC^3D; surface safety; surface change rate