Nd crystals have attracted considerable attention as promising gain media for high-power solid-state lasers due to their excellent thermal conductivity, mechanical properties, and favorable spectroscopic characteristics. In this work, a high-quality Nd single crystal was successfully grown by the Czochralski method, and its structural, spectroscopic, thermal, and laser properties were systematically investigated. The actual composition of the crystal was determined by inductively coupled plasma analysis, revealing an Nd³⁺ doping concentration of 0.85 at.%. X-ray diffraction combined with Rietveld refinement confirmed that the crystal maintains a cubic garnet structure with a lattice constant of 11.911381 Å, a unit-cell volume of 1689.985 ų, and a calculated density of 6.870 g/cm³. The optical transmission, absorption, emission spectra, and fluorescence decay characteristics were measured to evaluate the potential for laser applications. The absorption cross section at 808 nm was calculated to be 2.0 × 10^-20 cm² with a full width at half maximum of 8.02 nm, indicating efficient absorption of diode-laser pumping. The strongest emission peak was located at 1064 nm with an emission cross section of 1.85 × 10^-19 cm², and the fluorescence lifetime was determined to be 266 μs. Furthermore, the Judd–Ofelt theory was employed to analyze the radiative properties of Nd, and the calculated intensity parameters Ω₂, Ω₄, and Ω₆ were 0.26, 3.49, and 3.95, respectively, demonstrating good agreement between the theoretical and experimental results. The thermal distribution and thermal stress evolution under laser pumping were further investigated using COMSOL simulation, revealing a maximum temperature of 364.42 K and a maximum thermal stress of 65.86 MPa. Finally, continuous-wave laser experiments at 1064 nm were performed, and a maximum output power of 8.10 W with a slope efficiency of 40.03% was achieved using a 40% output coupler. These results demonstrate that the Nd crystal possesses excellent optical quality, favorable thermal stability, and high laser output capability, making it a promising gain material for high-power solid-state laser applications.