The "Sino-Russian-Mongolian National Strategic Interaction and Research on the Construction of the 'Belt and Road'" is a major project of the key research base of humanities and social sciences in universities. The trilateral cooperation between China, Russia and Mongolia is a major theoretical and practical issue in Northeast Asia that needs to be studied in depth. In recent years, the strategic position of China-Russia-Mongolia cooperation in Northeast Asian regional cooperation has been highlighted. In June 2016, in Tashkent, the capital of Uzbekistan, the three heads of state of China, Russia and Mongolia witnessed the signing of the cooperation agreement on the "Plan for the Construction of the China-Mongolia-Russia Economic Corridor". The construction of the Russia-Mongolia Economic Corridor has become an important carrier for the strategic docking and comprehensive cooperation of the three countries. Reinforcing the construction of the China-Russia-Mongolia Economic Corridor will become a major strategic aspect of future cooperation in Northeast Asia, which will have a major impact on the structure of Northeast Asia and the future trend of regional cooperation. This project studies the path of the cooperation between China, Russia and Mongolia, analyzes the significant impact of China-Russia-Mongolia cooperation on the structure of Northeast Asia, and can enrich and develop related theories such as international political economy.