Currently, driven by the accelerated iteration of digital technologies such as big data, cloud computing, and artificial intelligence, the digital economy has become a crucial engine for generating new quality productive forces and promoting industrial upgrading. Building on a systematic review of the theoretical evolution and measurement methods of the digital economy and new quality productive forces, this paper outlines their enabling mechanisms, industrial synergy pathways, and policy practices, and summarizes regional disparities and spatial spillover effects. The main findings are as follows: First, the digital economy reshapes the traditional factor structure and significantly enhances total factor productivity through the permeation of data elements and technological innovation; Second, driven jointly by the consumer internet and the industrial internet, it optimizes supply–demand matching and service models while reducing operating costs and improving production efficiency; Third, policy environments and institutional coordination amplify the enabling effects, as evidenced notably in national big-data pilot zones and the “East Data West Computing” initiative. Looking ahead, empirical research should deepen the exploration of micro-level mechanisms and dynamic panel analyses, construct a measurement system of new quality productive forces that spans macro, meso, and micro scales, and investigate pathways for regional collaborative governance and green digital integration to address the complex challenges of the new era.