Abstract: Since the founding of the People's Republic of China, in the process of exploring and building socialism with Chinese characteristics, China's comprehensive strength has been gradually improved and enhanced in the past for seventy years on the whole, despite serious setbacks that hindered normal development, especially after the reform and opening up. China has made great achievements in economic and other aspects. The reason is multifaceted. In addition to adherence to the correct guiding thoughts and strengthening party leadership, etc. another very important reason is that Chinese Communist Party regards reform and opening up as the basic national policy and never wavers over it. Therefore, reviewing the course of reform and opening up and exploring its nature and characteristics is helpful to understand and grasp the experience and lessons of China's seventy years' construction. It also helps to grasp and implement the "four self-confidence".