Abstract: In order analyze the influence of underground mining to surface complex buildings and structures of Langyashan Copper Mine,the surface terrain and underground mining model is established,the surface subsidence caused by underground mining activity is simulated by numerical simulation method.The results show that the maximum surface subsidence value is 48.4 mm,and the distribution and spread of each subsidence area are uniform,maximum values of inclined deformation,curvature and horizontal deformation are less than the allowable indexes.The subsidence deformation obtained by numerical simulation is modified by the monitoring data acquired by the main monitoring line and auxiliary monitoring line arranged by means of simulated monitoring method.The maximum subsidence value of main monitoring line is 45.99 mm,the values of auxiliary monitoring line is consistent to the ones of main monitoring line.The study results show that the area near the maximum subsidence are is uniformly deformed,the mining activity has little influence on the safety of surface buildings and structures,which also provides a theoretical basis for the prevention and control of geological disasters in mines.