Using the methods of the Gutenberg magnitude energy experience formula and the Benioff seismic strain energy release curve，we make a systematic study on seismic strain energy release of historical earthquakes within the southeastern margin of the Qinghai-Tibetan Plateau since 1500. The paper provides a periodic table of the earthquake strain energy release in the fault zone and the fault block region. The study shows that seismic strain energy release is strong in the east and south，and weak in the west and north. The overall seismic strain energy release of the Yushu-Xianshuihe-Xiaojiang fault system is consistent with the quasi periodic pattern. The earthquake cycle of some faults and broken blocks has some synchronization phenomena. The risk could not be ignored in the current period of the large release period of the southeastern margin of the Qinghai-Tibetan Plateau. Local analysis results show that seismic risk is very high on the Anninghe river-Zemuhe river fault and Xiaojiang faults. These dangerous zones need follow-up researches. In the future，it is necessary to combine different research methods to improve the reliability of seismic risk assessment.