The deformation monitoring and analysis in the process of dismantling inner support is crucial. In this paper,a super deep foundation pit engineering was taken as the research background,the rule of a deep horizontal displacement of the supporting structure,ground settlement,vertical settlement and axial force of support in the demolition process of support were monitored and analyzed. It was obtained that the settlement of surface ground around the foundation shows spatial and temporal clearly and the distribution of deep horizontal displacement of supporting structure is similar to the parabolic whose the maximum point constant upward shift with supporting continuous removed. Soil pressure of supporting shared with support removing process changed obviously,and the earth pressures of lateral support sharing show increasing trend. From the monitoring results,the demolition scheme is reasonable and effective and meets with the requirements of design and environment.