In order to give full play to the tensile properties of carbon fiber boards (CFRP), and improve the load-bearing capacity of prestressed concrete cylinder pipe (PCCP), a method of reinforcement with circumferential prestressed carbon fiber board in PCCP was proposed. By comparing the mechanical model calculation results of Lame’s formula with the finite element calculation results, it is concluded that the two results are basically in agreement. The maximum difference is only 9.3%. The cases of the same total wire broken rate with different broken distribution were calculated and studied, and it is found that the worst case is that the broken wires are at the same position. When wires break, the concrete damage index near broken wires increases from inside to outside. The reinforcement effect of PCCP with 10% of wire breakage rate was studied. When the wire breakage rate was 10%, the stress and strain of concrete and steel cylinder at the broken wires were significantly reduced under normal working water pressure, which indicates that CFRP has a very good reinforcement effect. The higher the wire breakage rate, the better the effect of CFRP before the concrete inner wall is damaged. This method also has the characteristics of short construction period, non-excavation, and easy operation, and has a good reference for actual PCCP emergency repair.