The invention discloses a phase modifier and SVC coordinated control method and system for inhibiting continuous commutation failure. The operation state data of a power grid is acquired, and the operation states of the power grid comprise a steady-state stage before a fault, a transient state stage after a fault, and a stage after the stability of the power grid system is restored. When the powergrid system does not fail, a phase modifier adopts a constant reactive power control mode, and an SVC adopts a constant voltage control mode. After a fault occurs to the power grid system, the phasemodifier is switched to a constant voltage control mode, and the SVC is controlled according to a locking criterion or an unlocking criterion. After the stability of the power grid system is restored,the phase modifier is reset to be in a constant reactive power control mode according to a bus voltage criterion of a converter station, and the SVC is reset to be in a constant voltage control mode.The method and the system have the advantages that the phase modifier and the SVC are controlled in multiple stages according to different operation states of the power grid, the resultant force effect of multiple reactive power sources is brought into full play, and the risk of direct-current continuous commutation failure is reduced.