The invention discloses a novel compound switch for reactive power compensation of a power distribution system. The compound switch comprises a control chip, a zero-crossing detection circuit, a thyristor and a relay; the novel compound switch is characterized in that the control chip is connected to a reactive power compensation controller, the relay, the thyristor and the zero-crossing detection circuit separately; the thyristor is connected between a three-phase power grid and a capacitor bank; the relay is connected with the thyristor in parallel; the zero-crossing detection circuit is connected between the three-phase power grid and the thyristor; and the control chip receives a switching signal input by the reactive power compensation controller. Accurate zero crossing and quick switching in reactive power compensation of the power distribution system are achieved, reactive power compensation of the system is achieved, the transient time is short, the impact in the transient process is small, the power quality of the system in the transient process is improved and the power supply reliability is improved.