The single phase β-Y2Si2O7 nanowires were synthesized via a facile molten salt method. The phase composition, microstructure, formation mechanism and the phase transformation of the β-Y2Si2O7 nanowires were investigated, as well as the thermal properties of the corresponding β-Y2Si2O7 ceramic. Results show that the molten salt method can effectively decrease the synthesis temperature. Furthermore, the molten salt temperature has a crucial influence on the crystal phase composition and the crystal morphology. The obtained β-Y2Si2O7 nanowires possess low thermal conductivity (1.84 W m−1 K−1) and low thermal expansion coefficient (3.88 × 10−6 K−1), which make them a promising candidate toughening material on coatings.