The Qinghai Tibet region, known as the Roof of the World and the Water Tower of Asia, has the largest number of lakes in the world, and because of its high altitude and the near absence of disturbance by human activity, the Tibetan plateau has long been a significant place to study global climate change. Hydrological stations cannot be easily set up in this area, and the in-situ gauge data are not always publicly accessible. Satellite radar altimetry has become a very important alternative to in-situ observations as a data source. Estimation of lake water levels with a given radar altimeter is often limited by temporal and spatial coverage, and therefore multi-altimeter data are used to monitor lake levels. Restricted by the accuracy of waveform processing and the intervals period between different altimetry missions, the accuracy and the sampling frequency of the water level series are low. By processing and merging 8 different altimetry missions, the developed data set gives the water level changes for 364 lakes (larger than 10 km2) in Tibetan Plateau from 2002 to 2021. The period of lake level change series with high accuracy can be much longer in many lakes. This data set and associated approaches are valuable for calculating the lake storage changes, trend analyses of lake level, short-term monitoring of lake overflow, flooding disasters on the Tibetan Plateau, and the relationships between the lake ecosystem change and water resources change.