Abstract: To investigate stress evolution and surface subsidence of pillars under repeatedly excavation and disturbance，combining with physical prototypes of a typical iron deposit，a numerical model of 3 stages and 15 stopes is built based on finite element theory and using Midas/GTS software.The stress evolution and surface subsidence of pillars under repeatedly excavation and unloading disturbance are numerically simulated.The results show that during the excavation of adjacent stopes in horizontal and vertical directions，the rating of stress disturbance shows as stope itself excavation﹥adjacent stope excavation at the same level﹥adjacent stope and diagonal stope excavation at the lower level﹥adjacent and diagonal stope excavation at the upper level.Horizontal X direction stress concentration is greater than the horizontal Y direction and the vertical Z direction.With the excavation of stope，the subsidence at the upper panel of orebody occurred and the uplift at lower panel occurred.The surface displacement area at first horizontal excavation extends along the orebody.The surface displacement area at second and third horizontal excavation has no obvious increase，while the sensitive subsidence areas tends to grow.

Key words: Dynamic disturbance, Hard rock, Pillar, Stress evolution, Surface subsidence