Abstract: The platform economy drives China's high-quality economic development through an intrinsic mechanism that represents a systematic progression from micro-level innovation to macro-level ecosystem evolution. The innovation-driven mechanism facilitates technology diffusion and paradigm shifts, fundamentally restructuring collaborative innovation systems. The industrial chain upgrading mechanism achieves a transition from one-way enablement to comprehensive chain enhancement, primarily through bidirectional empowerment that optimizes factor allocation and deepens the "four-chain integration". The industrial ecosystem construction mechanism establishes open platforms, stimulates value co-creation, and implements dynamic governance to realize symbiotic evolution among participants. The resource allocation optimization mechanism must incorporate sustainability constraints while pursuing efficiency improvements and structural evolution. This study contends that transcending capital-dominated development logic is imperative, and that guiding these four mechanisms through socialist economic principles is essential to channel the platform economy's vitality toward serving national strategies and common prosperity, thereby fully unleashing its potential to drive high-quality development.