Disclosed are a phase modifier and static var compensator coordination control method and system. The method includes the following steps: when an alternating current-direct current system is in a steady state, comparing system reactive power with a reactive power reference value, determining a power state of the alternating current-direct current system, and making a first cooperation control strategy of a phase modifier and a static var compensator according to the power state; and when the alternating current-direct current system is in a transient state, comparing system voltage and a voltage reference value, determining a power state of the alternating current-direct current system, and making a second cooperation control strategy of the phase modifier and the static var compensator according to the power state. The phase modifier and static var compensator coordination control method and system can fully utilize the ability of the cooperation control of the phase modifier and thestatic var compensator to provide reactive power and voltage support for the alternating current-direct current system for different working conditions. The strategy method provided by the inventioncan be used for dynamic reactive power compensation of the system by reactive power compensation device to effectively switch the phase modifier and the static var compensator, and so the phase modifier and the static var compensator can support the system voltage to a greater extent.