In this study, the specific heat of molten salt nano-eutectic (Li2CO3-K2CO3 doped with SiO2 nanoparticles) was theoretically and computationally investigated. The effective specific heat of a nano-eutectic can be significantly enhanced by the formation of needlelike nanostructures by salt eutectic. To investigate the effect of the formed nanostructure, its specific heat was theoretically calculated by a theoretical model. The mass fraction of the formed nanostructure was estimated by matlab. The theoretical prediction made a good agreement with the measured specific heat values from the literature with an error less than 3%. Additional verification of the proposed model was performed by a Molecular Dynamics simulation study. The simulated specific heat of pure molten salt eutectic made a good agreement with the literature value (1.6 kJ/kg °C with an error less than 1.7%). The simulated specific heat of nano-eutectic was 2.017 kJ/kg °C. The error between the theoretical prediction and the simulation is only 3.4% and the value made a good agreement with the experiment (1.9% max. error). The result shows that the enhanced specific heat of a nano-eutectic can be explained by the contribution of the formed nanostructures.