Abstract: Considering importance of mill load parameter on-line measurement in realization operational optimization and control of the mineral grinding process, ball mill grinding mechanism numerical simulation and mill load parameters soft measurement for the mineral grinding process were reviewed. First, the mill load was described based on the actual grinding process. Then, definitions of mill load, mill load parameters and mechanism model among them were reviewed, and the mill load detection framework was given out. Second, current status of numerical simulation analysis for the grinding process was reviewed, and the difference between the grinding mechanisms of different ball mills was given out and the possibility of soft measuring mill load based on support of numerical simulation was discussed. Third, mill load parameter soft measurement methods & techniques based on multi-component mechanical signals were reviewed in detail. Finally, the developing trend and the problems that need to be solved were summarized. Results show that the soft measurement of ball mill load parameters is difficult using the normally method. An intelligent soft measuring model with characteristic that simulate domain experts' dynamic cognition and compensation mechanism must be constructed. Moreover, the shortcomings of domain experts should be overcome. Thus, the intelligent soft measurement of mill load parameter can be realized.