Three basic essentials, which affect the inversion results of mechanical parameters, were systematically summarized for earth-rockfill dams, including inversed parameters, inversion methods and measured data. Recent research progress on inversion technology were also reviewed in four aspects, which can be summarized as follows. (1)Intelligent back analysis algorithms were developed. (2)Multi-parameter decoupling methods were put forward for multi-material and multi-model inversion problems. (3)Optimization methods for measuring points arrangement were developed, as well as the pre-treatment methods for measured data, including observation error treatment and virtual measurement supplement. (4)The uniqueness of inversion results can be evaluated by correlation analysis and trial simulation, which is closely related to the engineering characteristics and essentials of parameter inversion. Along with the expansion of earth-rockfill dam’s scale and the innovation of material and structure, it is necessary to develop new real-time inversion techniques and suitable inversion method for the dams with new materials or structure.