The invention discloses a high-voltage direct-current power transmission continuous phase-change failure prediction and reactive emergency control method based on extinction angle criteria. Parametersof the inverter side current-conversion bus voltage, a firing angle and an extinction angle are collected according to the work condition that a high-voltage direct-current power transmission systemoperate stably; transient-state real-time parameters of the inverter station current-conversion bus voltage, a firing angle and an extinction angle under faults are collected according to an expectedfault type; with a phase-change area method as the analysis basis, a minimum extinction angle expression required by successful direct-current phase change under the fault situation is deduced throughthe phase-change equivalent area method; the extinction angle criteria are calculated according to the extinction angle expression and the collected system-related stable-state and transient-state parameters; according to comparison between the extinction angle criteria and the real-time extinction angle, whether the continuous phase-change failure risk exists or not is determined, if yes, the next step is conducted, and if not, execution is completed; and reactive emergency control is started according to the continuous phase-change failure criteria. The purposes of accelerating system recovery and even resisting continuous phase change failure can be achieved.