The invention relates to a hydrogenation method of crude isopentene. The method comprises the following step: carrying out hydrogenation reaction on a crude isopentene distillate material through a fixed bed catalyst bed in the presence of a CO-H2 gas mixture. The volume liquid hourly space velocity is controlled at 4.0-12.0 hr<1>, the system pressure is controlled at 0.5-2.0MPa, and the reactant feed temperature is controlled at 30-80 DEG C. In the crude isopentene distillate material, the feed mol ratio of hydrogen to crude isopentene distillate is (1-1.5):1 on the basis of isoprene, and the volume percent of CO in the CO-hydrogen gas mixture is 0.0005-0.0020%. The catalyst is a spherical Pd/Al2O3 supported catalyst of which the particle size is 3-5mm, and the weight percent of Pd in the catalyst is 0.25-0.32%. The hydrogenation process can convert isoprene in the crude isopentene distillate into isopentene and effectively inhibit the isomerization reaction of 1-pentylene on the premise of keeping other hydrogenation conditions unchanged, thereby enhancing the content of the 1-pentylene in the hydrogenated crude isopentene.