The utility model provides an experimental synthetic return circuit synchronization control device of power frequency continuous current breaking capacity. Install including power frequency oscillating circuit and the power frequency vibration start up detecting unit that connects gradually, trigger phase control unit, photoelectric conversion and ignition unit. The utility model discloses can avoid having improved time control accuracy through detecting the delay problem that combined floodgate contact or loop current signal brought, reduce self loop electromagnetic coupling interference, effectively avoid the conducted interference of interference of space electromagnetic coupling and power supply circuit to invade, guarantee the operation of circuit safe and reliable, effectively avoid because of the spurious triggering occurence of failure that the system starts in the power frequency, temporal heavy current electromagnetic interference is lighted a fire in the impact and the high electromagnetic pulse space coupling brings, the operational reliability and the security that improve the system.