The mechanical response of heterogeneous rock masses under multi-field coupling conditions is central to geo-energy development and underground storage. This study synthesizes key insights from Session 49 of the second “International Geo-Energy Frontier Forum”, entitled “Multi-field Coupled Mechanics of Deep Heterogeneous Rock Masses”. Twenty-two experts and scholars presented their recent advances in heterogeneous-structure characterization, laboratory testing, mechanical mechanisms, and engineering applications. The discussion was organized around the experimental characterization of deep heterogeneous rocks, mechanistic links between local damage and fracture-network development under coupled thermal-hydraulic-mechanical-chemical conditions, and implications for energy development and underground storage. Perspectives distilled from these themes may provide useful guidance for optimizing stimulation schemes, assessing containment safety, and evaluating long-term reliability in deep geo-energy operations.