Taking“building a prosperous and happy socialist society”in the preamble of the 1954 Constitution as a logical reference, we can grasp Mao Zedong’s constitutional thought from the two basic elements of“national prosperity”and“people’s happiness”.“National prosperity”corresponds to the constitutional guidance of new China’s construction, and“people’s happiness”is reflected in the constitutional interpretation of people’s de? mocracy. Both of them are consistent with Mao Zedong’s exploration of the law of scientific constitution mak? ing. In terms of historical value, Mao Zedong’s constitutional thought is a model of Sinicization of Marxist con? stitutional theory, which enriched the system content of Mao Zedong Thought and promoted the development of the theory and practice of the constitution of People’Republic of China. To describe the historical picture of Mao Zedong’s constitutional thought in this period will not only help us understand the socialist constitutional thought with Chinese characteristics in the new era from the theoretical system, but also offer important lessons for the rule of law in the new era.