Due to the low design standards when constructed, limited construction materials, corrosion damage from natural environments and degeneration in normal use process, some reinforced concrete silos put up in the 1980s and 1990s are facing the troubles like decrease of bearing capacity, cracks and component damages, which are seriously affecting their normal use and bring certain security risks. Thus, the strengthening of these silos should be taken into account. In this paper, the positions that should be paid more attention when strengthened are obtained through finite element method analysis of a silo. Then the silo is strengthened with carbon fiber sheet through three different reinforcement conditions. The structure performances after being strengthened are analyzed, and the factors that affect the reinforcement effects are summarized.