The invention discloses a method for predicting deformation of a rock slope of a reservoir bank in a storage period. The method includes the following steps: establishing a reservoir bank slope deformation regression analysis predicting model comprising various deformation components, and carrying out regression analysis on slope deformation monitoring data; carrying out back calculation and analysis on rock-mass mechanical parameters and thermal parameters of the reservoir bank by using a numerical simulation and analysis method on the basis of the predicting model; calculating and analyzing deformation of the slope of the bank under the current water level by using the numerical simulation and analysis method on the basis of the rock-mass mechanical parameters and the thermal parameters, which are obtained by back calculation, of the slope of the reservoir bank, evaluating according to the deformation monitoring data, and adjusting parameters according to an evaluating result to obtain the adjusted rock-mass mechanical parameters and the thermal parameters; predicting deformation of the rock slope under a next storage level according to the adjusted rock-mass mechanical parameters and the thermal parameters to obtain a deformation prediction result of the rock slope of the reservoir bank under the next storage level; and inspecting a deformation predicting result. On the basis of the mixed predicting model, the predicting result is accurate and comprehensive.