The invention discloses a bypass circuit and a control method thereof, wherein the bypass circuit comprises: a first thyristor, an anode terminal of which is connected with a first output terminal ofa converter module, and a cathode terminal of which is connected with a second output terminal of the converter module; a second thyristor having an anode terminal connected to a second output terminal of the converter module and a cathode terminal connected to a first output terminal of the converter module; a first driving circuit connected to an anode terminal and a gate terminal of the first thyristor, respectively; a second driving circuit connected to an anode terminal and a gate terminal of the second thyristor, and a controller connected to the first driving circuit and the second driving circuit, respectively. The invention utilizes the bypass circuit to bypass the faulty converter module, which can not only save the floor space and reduce the cost, but also remarkably improve thebypass response speed, and the faulty converter module can be quickly bypassed all the time. The bypass circuit of the invention also has good mechanical characteristics.