By the method of longitudinal case study, it studies the evolution process of computer industry from the age of mainframes to the age of PC, and analyzes the dynamic mechanism of industrial modularization. It argues that the innovation strategy aroused by the competition of enterprises is the main driving force of industrial modularization. In the initial stage of the industry evolution, the strong incumbent enterprises will complete the transfer of product from integration to integration by radical innovation. In this context, the new entrants will enter from the “low-end value module” and use module innovation strategy to gradually break down the integrated valuechain monopolized by the incumbents. The new entrants will also use damage innovation technique and adopt “low-end customer entrance” and opening up technical standards strategies to damage the competitive advantages of the incumbents and speed up the industrial modularization.