The 2023 World Energy Outlook forecasts a significant role for renewables like wind turbines and photovoltaic systems in the future energy mix, highlighting the importance of energy efficiency and integrated energy systems (IES). While IES offers benefits through collaborative scheduling and multi-energy resource complementarity, challenges like supply-demand imbalances persist. Researchers have proposed solutions including integrating energy conversion and storage devices, and leveraging the flexibility of thermal inertia and demand response mechanisms. Hydrogen energy storage (HES) has emerged as a promising long-term energy storage option due to its long-term storage capability, zero pollution, and high energy density. Studies have shown that integrating HES in IES can effectively support seasonal energy storage and ensure balance on short and long-term scales. However, challenges like high investment costs and geographical limitations remain. Research continues to explore the optimal integration of HES in IES to tackle long-term supply-demand imbalances and enhance energy migration for economic benefits.