Detailed polarized spectral properties of a 0.685 at. % ${\mathrm{Nd}}^{3+}\text{:}{\mathrm{Sr}}_3{\mathrm{Y}}_2{({\mathrm{BO}}_3)}_4$ crystal grown by the Czochralski method have been investigated, including the absorption cross section, the emission cross section, and the fluorescence lifetime. The anisotropy of the spectral properties in different polarized directions was discussed thoroughly. The absorption and emission spectra of ${\mathrm{Nd}}^{3+}$ are found to be inhomogeneously broadened due to its internal disordered lattice. Additionally, the CW laser operation at 1.06 μm was also demonstrated for the first time. The maximum output power of 905 mW was achieved, with corresponding optical conversion efficiency of 10.8% and slope efficiency of 12.8%.