The “bringing in” and the “going out” of opening up to the outside world encompass eight major fields, respectively, with different levels of openness of each field and within each field. Advancing high-level opening-up not only requires expanding the scope of openness and raising the level of openness but also improving the level of openness in each field and optimizing the structure of openness. Opening up in the strategic sense is not the same as opening up in the tactical sense, and the latter requires highly rational and specialized decision-making. High-level opening up needs to correctly grasp and conform to the basic laws of opening up, and have an accurate understanding of the current situation and trends of one’s own country, other countries in the world, and the international situation. Some existing cognitive and judgmental errors, such as overestimating China’s economic growth rate, strength, position and influence in the world economic system, misjudging other countries’ foreign economic strategic orientations, and insufficient understanding of the laws of international relations, international order, and international governance system, need to be corrected. It is necessary to strengthen research on international issues, countries, and regions. Instead of simply thinking about and solving international problems with “Chinese thinking”, it is important to cultivate truly meaningful think tanks or intellectual markets through competitive mechanisms, accelerate the training of versatile talents for high-level opening up, actively seek long-term stable strategic cooperation with major countries like the United States, and allow different regions to choose different strategies, priorities, and paces for opening up.