Abstract: When TBM is used for construction in soft rock environment, TBM shutdown is often required in case of accidents such as jamming or equipment maintenance and replacement.Reserved deformation and shutdown time are the key to the safe operation of TBM.Based on the Liupanshan mudstone tunnel of Bailong River diversion project, according to the actual geological conditions, tunnel structure and TBM construction process, the deformation characteristics of surrounding rock and its interaction with shield under TBM shutdown were studied by numerical calculation method, and the reasonable reserved deformation and shutdown time were analyzed.The results showed that:(1) The sandy mudstone in the project was extremely soft rock with significant rheology and conforms to the CVisc and Burgers models.Sufficient reserve margin and rapid excavation could ensure the safe passage of TBM.(2) During the shutdown period, the deformation of surrounding rock had a significant time-space effect.The deformation was fast at first and then slow.The vertical displacement was greater than the horizontal displacement, and the displacement of surrounding rock in the shield rear was greater than that in the front.(3) The space-time effect of rock-shield interaction was manifested as a process of non contact-local contact-complete contact-strong extrusion from bottom to top and from back to front.(4) The safe shutdown time of TBM with reserved deformation of 10 cm should not exceed 7 days.The research results have theoretical reference significance for understanding the rock-machine interaction during TBM shutdown in soft rock.