The inverse velocity method (INV) based on the onset of acceleration (OOA) point is widely used in landslide time prediction. However, the selection of OOA point affects the accuracy of INV prediction results. This study proposed a deformation standard deviation-OOA (DSD-OOA) point identification method based on the statistical characteristics of ground-based radar landslide area deformation data. By introducing a controllable variable, a modified INV method was derived. The OOA point identified by DSD-OOA was substituted into the modified INV method for landslide time prediction and compared with the prediction results of the moving average-OOA (MA-OOA) point method. Results show that compared to MA-OOA, the inverse velocity time series after the OOA point identified by DSD-OOA exhibits smaller fluctuations and is closer to linear change. The INV predictions using MA-OOA (MA-OOA-INV) consistently lag behind the actual landslide time, while the INV predictions using DSD-OOA (DSD-OOA-INV) are more stable and consistently precede the actual landslide time of failure. Furthermore, the root mean square error (<em>RMSE</em>) and coefficient of determination (<em>R</em>²) indicate that the DSD-OOA-INV method predicts landslide lifetime with higher accuracy, suggesting that OOA points identified by the DSD-OOA method can more precisely predict landslide time of failure.