The invention relates to a preparation method of Y2SiO5 crystal whiskers, which comprises the steps of: dissolving Y (NO)3.6H2O and Na2SiO3.9H2O in anhydrous ethanol to obtain solution A; adding citric acid in the solution A and magnetically stirring at room temperature to obtain solution B; and placing the solution B in a hydrothermal reaction kettle for constant-temperature reaction, conducting centrifugal separation after a reaction system is naturally cooled to room temperature, successively washing with distilled water and anhydrous ethanol and finally drying to obtain the Y2SiO5 crystal whiskers. Compared with the traditional method, the preparation method of the Y2SiO5 crystal whiskers has the advantages that the purity of the Y2SiO5 crystal whiskers prepared through a solvent hydrothermal synthesis method is high, the fineness is ultrahigh, the grain size distribution range is narrow, the extent of particle aggregation is low, the crystal is fully developed, the process is relatively simple, the appearance and the size are controllable, the process is simple and high-efficiency, the cost is lower, the preparation temperature is low, the later-stage crystallization is not required, the possible defects that the crystal grains grow up, are coarsened or are curled and the like in the later-stage heat treatment process are avoided to some extent, and the like. By adopting the solvent hydrothermal synthesis method, high-purity Y2SiO5 crystal whiskers with controllable appearance are prepared under low-temperature condition.