The theory of the socialist market economy was born and developed amidst the grand practice of China’s reform and opening up and has been validated by the country’s rapid economic development. It represents both an innovation in contemporary economic theory and its practical application. The theory has gone through several transformative phases—a tortuous progression, initial formation, steady growth, and in-depth exploration—refining itself in practice. It achieved the organic integration of the basic socialist system with the market economy and dual breakthroughs in the innovation of economic theory and successful practice. This has significantly enriched Marxist political economy and modern economic theory, offering a new benchmark for assessing market economy models. Looking ahead, the theory of the socialist market economy will continue to evolve, exerting a profound impact on the once-in-a-century global transformation and contributing to the building of a shared future for mankind.