This paper is a pioneering work in its field that reveals and studies significant events,critical nodes,and important chains during the Three-Year Economic Difficulty period in the history of New China.This is done from the perspective of central senior leaders and their internal reference instructions.The financial internal reference instructions endorsed by Li Xiannian has precious historical value.They give us abundant internal information and historical truths and enable us to understand many historical details of the special era.What's even more rare is that it lets us personally feel how Li Xiannian and other older generations of proletarian revolutionaries worked wholeheartedly and tirelessly for the party,the country,and the people,ultimately leading the people to defeat the catastrophic disaster and overcome unprecedented difficulties.The author believes that the Three-year Economic Difficulty period may be the last production-oriented"civilization growing pains"that occurred in the historical process of China's transition from an agricultural society to an industrial society.