Sino-US relations are the most important bilateral relations in the world. Regrettably, there is a major problem in Sino-US relations at present, that is, the United States regards China as a strategic competitor, which makes Sino-US relations seriously retrogress. The United States believes that the Belt and Road Initiative proposed by China, the establishment of AIIB and the online operation of Shanghai oil futures all pose a serious threat to American hegemony, especially the rapid development of China in science, technology and manufacturing. American politicians regard China's development not as an opportunity but as a threat, and Trump is no exception. He signed a series of new bills on Taiwan, increased arms sales to Taiwan, launched a trade war against China, and constantly engaged in so-called freedom of navigation in the South China Sea, which changed Sino-US relations from competitive cooperation to competitive non-cooperation. On the Syrian issue, China has always stood with Russia, advancing and retreating together with Russia in the Security Council, forming a strategic synergy between China and Russia on global issues, including China. When the United States engages in unilateralism and trade protectionism in the economy and bullies the weak and fears the hard in the military, China hides its strength and bides its time. However, when the United States stepped up its containment and containment of China, which directly affected China's national interests, China began a new foreign policy that made a difference and began to counter all kinds of bullying by the United States. Since the United States regards China, Russia and Iran as its biggest competitors, China, Russia and Iran will inevitably form a strategic cooperative relationship, especially the relationship between China and Russia is back to back. If Russia is defeated by the United States and western groups, China will face the powerful United States alone. If we can support the Russian strategic containment of the United States in Syria, it will certainly reduce the strategic pressure of the United States on China in the Western Pacific. Besides, in the international arena, especially in the UN Security Council, we can support each other. The US military attack on Syria directly threatens Russia and indirectly threatens China. Therefore, China cannot stand idly by and give Russia, Syria and Iran firm support in some way. This is the need of national grand strategy, because if Russia loses, China will not be able to face the siege of the whole western group led by the United States alone.