The special natural conditions of Tibetan Plateau have led to its low level of urbanization development. Understanding the spatio-temporal pattern and causes of urbanization development in Tibetan Plateau has important guiding significance for promoting future New-type Urbanization. Based on the population census data from 1990 to 2020, this paper analyzes the spatial and temporal changes of the urbanization level of county units in Tibetan Plateau, and uses geographical detector to analyze the natural driving factors leading to the formation of urbanization pattern. The results show that the overall urbanization level in Tibetan Plateau is low, the urbanization rate fluctuates greatly, and the regional differences are obvious, and the differences tend to decrease. The areas with higher urbanization level are concentrated in the administrative center and the eastern edge of the plateau, and some areas in the middle of the plateau still have a decline in urbanization rate. Topographic factors are the main natural factors affecting the development of urbanization in Tibetan Plateau.