Abstract: In May 2018, the United States has announced the resumption of comprehensive sanctions against Iran, and Iran once again became the focus of international attention.In this paper we systematically review the energy endowment of Iran and its status of the energy exploration and utilization.In addition, we analyze its advantages for China's energy security.We show that the guarantee level of Iran's oil for China's oil security has an increasing trend from 1997 to 2017, and Iran is of great significance to maintain China's gas resources supply security.China-Iran energy cooperation has strategic complementarity, geopolitical and economic advantage, historical and cultural foundation and the advantage of reducing dollar-denomination risk.On the basis of the above research, we dissect the influence of the comprehensive sanctions against Iran on China's energy security in terms of supply price, supply channel and transportation security.Finally, we proposed some countermeasures and suggestions to avoide the risk of U.S. sanction and safeguard national energy security.