Securing global net zero carbon emissions by mid-century has moved towards the top of agenda for most countries in the world. Green or renewable energy has become vital in achieving this challenging target and the key enabling technology is energy storage infrastructure, due to the intermittent or seasonal nature of the renewable energy. Mineshaft thermal energy storage (MSTES), as a new energy storage technology, has significant potential to provide large-scale storage capacity, long-term storage duration, numerous storage sites, and limited surface footprint. Ensuring long-term functionality and stability of MSTES structures is crucial for sustainable energy storage and supply. However, the working environment in MSTES is complicated, imposing fluctuating temperatures, high water pressure and chemical corrosion. Under these multiphysical effects, concrete linings of the mineshafts may experience serious degradation over time, compromising the structural performance and reducing the service life of MSTES. To explore the degradation evolution and deterioration mechanisms of concrete under MSTES environments, this study proposes a new experimental strategy by combining a multiphysical experimental platform and a bespoke real-time monitoring system. The multiphysical experimental platform adopts an environmental chamber and an aging cell to replicate the in-situ MSTES conditions (e.g. temperature fluctuation, pore water pressure and chemical corrosion). The monitoring system utilises a time-lapse camera and digital image correlation technique to capture the temperature fluctuation induced expansion and shrinkage deformation of concrete over the time. Besides, X-ray computed tomography and scanning electron microscopy are also adopted to help identify the microstructural and microcrack evolution. By correlating mechanical properties, deformation and fracturing evolution, and microstructural characteristics, the obtained results can provide valuable information and reference for understanding the deterioration behaviour and failure mechanisms of concrete under the complicated MSTES conditions and further estimating the serviceability and durability of MSTES facilities.