Quantum memory is a crucial element in large-scale quantum networks. Integrated quantum memories based on micro-/-nano structures, such as waveguides, could significantly enhance the scalability and reduce the consumption of optical and electrical power. ¹⁵¹Eu ³⁺:Y ₂SiO ₅stands out as an exceptional candidate material for quantum memory, because it possesses a spin coherence lifetime of 6 hours and an optical storage lifetime of 1 hour. Here we employ focused ion beam technology to fabricate a triangular nanobeam on the surface of a Y ₂SiO ₅crystal. The width and length of the nanobeam are 2 µm and 20 µm, respectively. The optical lifetime and inhomogeneous broadening of ¹⁵¹Eu ³⁺in the triangular nanobeam are measured by fluorescence spectroscopy. The optical lifetime is 1.9 $\pm$ 0.1 ms and the optical inhomogeneous broadening is 1.58 $\pm$ 0.05 GHz at a doping level of 0.07% for ¹⁵¹Eu ³⁺. The hyperfine transition spectra are measured using optically detected magnetic resonance and a spin inhomogeneous broadening of 19 $\pm$ 3 kHz is obtained. Furthermore, we analyze the coherence property of optical and hyperfine transitions separately via transient spectral hole burning and spin echo measurement. We obtain a optical homogeneous linewidth down to 22 $\pm$ 3 kHz which is still limited by the instantaneous spectral diffusion and a spin coherence lifetime of 5.1 $\pm$ 0.6 ms at the geomagnetic field. The results demonstrate that ¹⁵¹Eu ³⁺embedded within the 2 µm triangular nanobeam essentially retain the same optical and hyperfine transition properties as those observed in bulk crystals. Consequently, this research establishes a foundation for integrated quantum memories based on ¹⁵¹Eu ³⁺ensembles and the detection of the single ¹⁵¹Eu ³⁺ion based on the focused ion beam technique.