Abstract: The in-situ leaching process of ion-type rare earth is a typical complex nonlinear system with numerous influencing factors and interactive coupling. It is challenging to quantitatively describe the relationship between leaching conditions and leaching rate through constructing a mechanistic model. This study the in-situ leaching process of ionic rare earth, based on the principle of multiple nonlinear regression and the column leaching simulation experiment results. Independent variables included ore grade, leaching agent concentration, leaching flow rate and the average concentration of mother liquor, and the dependent variable was the leaching rate of rare earth. A prediction model and calculation system for the rare earth leaching rate were established to build the quantitative relationship between process conditions and leaching rate. The results of the model test and analysis show that the reliability and prediction accuracy of the model were high, and the prediction accuracy of the rare earth leaching rate could reach 97.785%.