Blasting excavation damaged zone (EDZ) is regarded as a heterogeneous and unsteady three-dimensional disturbed field evolving with the excavation progress; and the mechanical parameters in EDZ are identified as a parameter field of time-space evolution characteristics. A displacement back analysis method is proposed for parameter field identification of the EDZ around openings in practical working state

considering the spatial effect of blasting disturbance and real deformation response of rock mass. Based on the spatial displacement field obtained by space interpolation of local monitoring displacements

by analyzing the deformation disturbance mechanism of the surrounding rock

a numerical model for parameter field of rock mass deformation modulus in EDZ is put forward; and the applicability and parameters sensibility are further analyzed. Taking the deformation modulus for instance and combining the measured displacement of surrounding rock

the dynamic implementation progress of the displacement back analysis for parameter field is introduced in detail. Finally

the method is applied to the parameter field identification and dynamic feedback analysis and prediction of stability assessment of the surrounding rock during construction of Xiluodu underground caverns. It is shown that the method is reasonable and effective and of significant engineering applicability and practicality for fast feedback analysis of monitoring and stability assessment during construction of large-scale underground caverns.