The initial time of collision of the Indian Plate with the Eurasian Plate, or the uplift time of the Tibetan Plateau, is an important and controversial scientific issue. Thus far, the main means of studying this problem have been geology or geography, and we have attempted to carry out exploratory research through modern geodesy. In this study, GNSS observations of the displacement field, surface mass migration load correction, hydrological model, CRUST1.0 model, and other data were used to estimate the uplift rate and thickness of the Tibetan Plateau block and then obtain the uplift starting point and uplift process of the entire Tibetan Plateau block. Finally, assuming that the Tibetan Plateau block was a linear uplift, we estimated that the initial time of the collision between the Indian and Eurasian Plates was 83 Ma. If the Tibetan Plateau underwent nonlinear uplifting, the initial collision time between the Indian and Eurasian Plates would be closer to the geological results. This study provides a new method to study the starting time of block uplift on the Tibetan Plateau.