Abstract: Mountain highway tunnels consume substantial energy during operation. Utilizing clean energy sources like photovoltaic (PV) power to partially or fully meet tunnel energy demands represents a crucial approach to alleviate traditional energy shortages and achieve carbon neutrality goals. Based on the Wudingguan Tunnel PV power station project, this study establishes a comprehensive design and evaluation framework for highway tunnel PV energy supply systems, incorporating tunnel energy consumption analysis, solar resource assessment, PV-storage system design,and operational performance evaluation. The research provides specific design methodologies for highway tunnel PV stations and analyzes long-term monitoring data to reveal intrinsic relationships between PV power generation and weather/seasonal variations. Key findings include: (1) The Wudingguan PV station achieves an annual output of 9 ×105 kW·h, fully covering non-ventilation electricity demands (3.8 × 105 kW·h); (2) PV power generation shows strong weather dependence, with clear days yielding maximum daily average output (3 472.8 kW·h) and snowy days producing minimal output (less than 1/40 of that in clear days); (3) Grid-connected PV microgrid in Wudingguan tunnel effectively mitigates typical PV limitations like instability and low utilization efficiency ("junk electricity"characteristics).