This book attempts to establish a new theoretical framework to analyze the intrinsic patterns of economic growth, structural transformation, and the shift of economic momentum in the digital economy era. The book provides a detailed discussion on the interactions between the old and new economic sectors (the limitless and limited sectors), the migration of labor and capital between different sectors, as well as the accumulation of knowledge capital, such as data, technology, and creativity. Additionally, it delves into the growth mechanisms of the new dual economy. Given the characteristics of competition and deep integration between the limitless and limited sectors in the new dual economy era, the book also explores the transformation and digitalization of traditional enterprises.This book not only focuses on theoretical innovation and exploration but also closely relates to the realities of new economic development and China's economic transformation. It holds reference value for economic researchers, government departments and entrepreneurs.