Abstract: By setting up mechanics and numerical simulation model of overlying coal-pillar in extremely-thick and sub-erect coalseam，stress distribution of coal-pillar and surrounding rock was analyzed.It was obtained that rock-burst was influenced obviously by overlying coal-pillar.Rock-burst inducing mechanism was that under high horizontal stress，shear stress and elastic energy concentration zone formed at the edge of coal-pillar which was easy to result into rock-burst.Micro-seismic matters distribution and seismic source location result proved the mechanism of rock-burst induced by coal-pillar.On the basis of this，applying water injection and deep bore-hole blasting in rock and coal in shear stress zone，stress concentration degree was reduced effectively and elastic energy of coal and rock was released steadily，which reduced rock-burst danger.