Abstract: Elasto-plastic stress field around underground structures was analyzed,and the equivalent stress curve was obtained.It was indicated that the peak stress intensity existed around underground structures.The support pressure distribution was obtained and the mechanism of zonal disintegration of rock was analyzed.Splitting failure in the support pressure zone was the necessary condition for zonal disintegration formation.The stress disintegration in the support pressure zone was adjusted by diametrical compression formula.It was shown that the zonal disintegration of rock was related not only to the depth but also to the mechanical parameters of rocks.