Abstract: With the growing global demand for renewable energy, integrated photovoltaic-thermal energy storage systems have gained significant attention as an important technology for energy conversion and storage. However, optimizing energy storage capacity while ensuring high energy conversion efficiency remains a critical challenge that needs to be addressed. This paper proposes an optimization strategy for an integrated photo-thermal energy storage system based on fiber coupling and thermophotovoltaic technology. It employs fiber concentrators and Fresnel lenses for efficient solar energy collection and transmission, while the spectral selective filter reduces radiative losses, enhancing the energy conversion efficiency of photovoltaic cells. By optimizing the system's geometric parameters, the photovoltaic cell's bandgap, and the cut-off energy of the spectral selective filter, and using the Nelder-Mead algorithm for iterative optimization of key parameters, significant performance improvements have been achieved. Experimental results show that under a 5× solar concentration ratio and with a phase change material length of 10 cm, the system's energy conversion efficiency increased from 27.5% to 30.7%, while the energy storage capacity remained at 82%. These research results provide theoretical support and engineering practical value for the efficient energy conversion and storage of future integrated light storage systems.