A C4 fraction hydrogenation method is provided. The method includes: a step a) of dissolving a C4 fraction into an absorbent to obtain a feedstock mixture; a step b) of mixing the feedstock mixture with hydrogen, feeding the material mixture into a first-section reactor filled with a catalyst A, and performing hydrogenation; a step c) of mixing the reactor effluent of the first-section reactor with hydrogen, feeding the mixture into a second-section reactor filled with a catalyst B, and performing hydrogenation; and a step d) of separating the absorbent from the liquid-phase reaction effluent of the second-section reactor to obtain a C4 fraction hydrogenation product. The absorbent is one or more selected from benzene, toluene and cyclohexane. According to the method, the C4 fraction is dissolved with an inert solvent before hydrogenation, a two-section hydrogenation reaction process is adopted, unsaturated olefins in the C4 fraction are effectively subjected to hydrogenation saturation, high-quality cracking raw materials are provided, the problem that activity of a hydrogenation catalyst is liable to decrease is effectively overcome, and the hydrogenation efficiency is ensured.