Abstract: In order to improve the accuracy of rock deformation predictions, the general GM (1,1) model, reduced origin error GM (1,1) model, and holographic information unequal-step GM (1,1) model were established for an analysis of rock deformation prediction and accuracy based on monitored and measured data at DK405+825 of the Cuijiachong tunnel. The analytical results show that the predictions of the three grey models all met the requirements on accuracy, with the relative error of the reduced origin error GM (1,1) model being the lowest and the hysteresis error of the holographic information unequal-step GM (1,1) model being high.