Guided by the carbon peaking and carbon neutrality goals as well as the strategy of boosting China's strength in transportation development, promoting the deep integration of new energy vehicles (NEVs) with green energy and achieving self-sufficiency of green energy in transportation have emerged as a key pathway for ensuring national energy security and establishing a green transportation system. Considering the explosive growth of the NEV industry and the green low-carbon transformation of energy, this study analyzes the challenges of vehicle-energy integration during the 15th Five-Year Plan period in terms of planning, technology, and mechanisms, clarifies phased development goals, and proposes an overall framework for building a green energy network in transportation. Moreover, the study expounds on six development priorities of vehicle-energy integration: source-grid-load-storage collaborative planning, construction of new infrastructure, upgrading of technical equipment, collaborative safety control, big data intelligent dispatching, and innovation in market mechanisms. It also proposes four suggestions: formulating special development plans, increasing the construction of new infrastructure, improving vehicle-energy aggregation and dispatching platforms, and establishing a mechanism for integrating transportation with the electricity and energy systems. The research findings can provide theoretical support and practical guidance for promoting deep integration of vehicles and energy as well as constructing a "Third Grid of Green Power in Transportation" during the 15th Five-Year Plan period, thereby strengthening the coordinated development of China's transportation and energy sectors.