China’s new energy vehicle, photovoltaic and other industries have secured prominent competitive advantages in the global marketplace. This industrial reality verifies that technological diversity constitutes a vital manifestation of technological progress in emerging industries. Characterized by multi-hierarchical structural attributes and dynamic evolutionary properties, technological diversity exhibits complex evolutionary patterns. From a dynamic evolutionary perspective of technological progress within emerging industries, this paper systematically sorts out, discriminates and deconstructs the theoretical connotations of technological diversity. A multi-layer analytical framework consisting of the internal aggregation layer, technology expansion layer and industrial structure layer is constructed to elaborate three core mechanisms driving technological progress, namely technological recombination, technology spillovers and the evolution of industrial technological structure, which collectively delineate the dynamic operational logic of technological advancement in emerging industries. On this basis, this study establishes a“P-S-I” (Technological Portfolio Diversity-Sector Spillover Diversity-Industrial Technological Diversity) conceptual framework of technological diversity and develops a corresponding multi-hierarchical measurement system. Finally, this paper takes China’s crystalline silicon solar cell industry as the research sample to conduct empirical analysis, so as to deconstruct, quantify and interpret its technological progress from a dynamic perspective.