The modularized cluster is the equilibrium process of transaction efficiency, learning cost, and deepening of division of labor, and it is the mutual equilibrium process of economy of division of labor and transaction cost. Division of labor is conducive to technological innovation, which promotes the technology standardization degree and the development of modular technology and product modularization as well as its cluster. In turn, the development of product modularization and its cluster can reduce the transaction cost and improve the efficiency of trading, and thus to promote the evolution of the division of labor. Therefore, the modularized cluster is accompanied by the evolution of division of labor, the increasing of technology standardization degree, the lowering of transaction cost, the promoting of trading efficiency, and its formation and development has its inherent law.