The first development opportunity was Zheng He's voyage to the West. Last year was the 600th anniversary of the great voyage. Great geographical discoveries were made in the west through great voyages. The high profits (the export of cheap products and the plunder of colonies) brought by the great voyage stimulated the development of navigation and exploration, and also led to the collapse of the western feudal system. China's self-sufficient economy can't support expensive ocean navigation due to system problems, and China's concept of going to the country determines that the purpose of sailing is to show national strength, not to manage and develop overseas markets.
The second time was in the middle and late Ming Dynasty, when the seeds of Chinese and Western capitalism appeared almost simultaneously. However, due to the long-term closed door and the imprisonment of the Ming and Qing Dynasties (stereotyped writing and literary inquisition), China's capitalism has long been in the primitive stage;
The third time was in the fifty-seventh year of Qianlong (1792), when British Ambassador Magani visited China. This time, he brought the fruits of the British industrial revolution, including all kinds of finished products and models, as well as the most advanced British active weapons. At the same time, it requires free trade and consultation with the Qing government on the basis of reciprocity. However, under the influence of China's de-nationalization, all this was regarded as a roundabout way, and China lost its last chance to catch up with the world before the Opium War.