The Qinghai-Tibet Plateau (QTP) is the most unique region of human-land relations, and its main factor is population. By building a population and space dataset of the QTP at the township level from 1982 to 2017, this paper presents the pattern evolvement and regional distribution characteristics of township-level population in the QTP in detail for the first time. By using Geodetector method to analyze the influencing factors of township-level population change in the QTP, this paper provides scientific foundations for studying the Third Pole, ecological environment protection of the QTP, and human-land relations. The conclusions are as follows: 1) The population spatial distribution is not balanced at the township level, presents the regional differentiation characteristics of ‘dense in southeast and sparse in northwest’ along the ‘Qilian-Jilong Line’, and demonstrates the phenomenon of population center of gravity moving to the hinterland of the plateau at an accelerated speed; 2) The township-level population develops in a decentralized trend in general, and the cold- and hot-spot distribution of population has prominent spatial distribution characteristics. The population hot spots are concentrated in the surrounding areas of Xining, Golmud, Hotan and Lijiang; 3) The population of the QTP is increasing, and the inter-annual change of township population has a relatively stable regional regularity; 4) The level of per capita income is the leading factor in the change of township population, and its effect intensity is increasing continuously. The relative effect intensity of urbanization level and location conditions on population change has decreased significantly after 2000. The adaptability of living environment, such as topography and climate, has little influence on population change.