The catalytic conversion of naturally rich and renewable biomass into high-value chemicals is of great significance for pursuing a sustainable future and a green economy. The preparation of pentanediol from furfuryl alcohol is an important means of high-value conversion of biomass. The Pt-based catalyst supported on MgO was applied to the selective hydrogenation of biomass furfuryl alcohol to prepare pentanediol. By adjusting parameters such as catalyst loading, reduction temperature, reaction temperature, and pressure, a highly active catalyst was designed and the optimal catalytic hydrogenation conditions were determined. The hydrogenation experiment results showed that the selectivity of the 2Pt/MgO-200 catalyst for 1,2-pentanediol and 1,5-pentanediol reached 59.4% and 15.2%, respectively, under 160 °C and 1 MPa hydrogen pressure. The catalyst was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectrometer (XPS), CO2-temperature programmed desorption (CO2-TPD), and other methods. The characterization results indicate that the reduction temperature has a significant impact on the metal Pt, and an appropriate reduction temperature is beneficial for the hydrogenation performance of the catalyst. In addition, the basic sites on the carrier are also another important factor affecting the activity of the catalyst. In addition, stability tests were conducted on the catalyst, and the reasons for catalyst deactivation were studied using methods such as thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The results showed that the activity of the catalyst decreased after five cycles, and the deactivation was due to the hydrolysis of the carrier, the increase in metal particle size, and the surface adsorption of organic matter.