Advanced thermal energy storage (TES) is a pivotal research area in energy storage, utilizing sensible heat storage (e.g., molten salt, water), latent heat storage (phase change materials, PCMs), and thermochemical heat storage (reversible chemical reactions) to achieve efficient thermal energy storage and release. Its core objectives are enhancing energy efficiency, addressing renewable energy intermittency, and supporting carbon neutrality. Sensible heat storage, with mature technology and low costs, is widely used in solar thermal power and industrial waste heat recovery. Latent heat storage, leveraging the high energy density of PCMs, excels in building energy efficiency and thermal management of electronic devices. Thermochemical storage, with ultra-high energy density and long-term lossless capabilities, is critical for high-temperature industrial processes and seasonal storage. The technology holds vast potential in renewable energy integration, industrial energy conservation, building heating/cooling, power grid peaking, and transportation thermal management. However, challenges such as material cycling stability, system heat loss, and high costs remain. Future advancements focus on innovative composite PCMs, engineering high-temperature thermochemical systems, intelligent multi-energy integration, and policy-driven large-scale deployment. As a cornerstone of flexible, low-carbon energy systems, advanced TES is poised to accelerate global energy transition and structural transformation.