The reinforcement scheme of pregrouting + realtime tracking grouting of large settlement points of high building is proposed. The differential settlement and horizontal displacement of the building is effectively reduced by Soletanche grouting to 2 m below foundation of the building; the ground surface around the building and the horizontal displacement of foundation pit supporting pile are obviously reduced; and the axial force of steel support is improved; the inclination of the building and the differential settlement of the foundation can meet relevant requirements. Some appropriate key construction and control technologies for different deep foundation pit construction phases are proposed; and the cracks of the building are monitored. The monitoring results show that the sizes of the existing cracks of the building are essentially invariant; and 45 increased cracks occurred to wall belong to temperature shrinkage cracks. The calculation and monitoring results show that the differential settlement and deformation of the building can be effectively controlled by pregrouting and realtime tracking grouting of large settlement points of the high building; the safety of the building and the foundation pit can be guaranteed; the calculation results of the model coincide with the monitoring results well; and the grouting scheme adopted is rational and economical.