In order to study circular chamber excavation and supporting process of soft rock mechanical mechanism, the model of soft chamber was established firstly. Based on Mohr-Coulomb yield criterion,rock mass characteristics such as rock dilatancy 、softening and so on and were considered. Therefore, chamber rock elastic-plastic solutions in excavation process was deduced. Secondly, based on homogenization method under the condition of bolts and liners supporting, considering the coupling effect between anchor and surrounding rock and the aging characteristics of primary lining concrete, rock elastic-plastic solution under supporting condition was obtained. Lastly, an example was analyzed to study the effect of different factors such as , supporting opportunity and so on to stress of plastic zone、surrounding displacement and plastic zone radius of chamber. Based on theoretical research case, the change rule of considering the "space effect" and the supporting opportunity when calculating the subarea of the chamber, the control of interval distance of rock bolts on the displacement of surrounding rock mainly reflecting in the residual area, the role of dilatancy factor in the hardened area, the "spatial effect" in excavation and the support time to control the displacement of surrounding rock can not being ignored are revealed. The results of this paper provide a certain theoretical foundation to process of deep-buried soft rock chamber excavation and supporting.