The invention discloses a synchronous trigger circuit for multiway Trigatron gas switches. The circuit comprises a high voltage direct current power supply, a charge resistor, a sphere gap, a pulse transformer, N discharge resistors and N energy storage capacitors. The number of the Trigatron gas switches is N. The synchronous trigger circuit is characterized by rapid voltage rising edge, high voltage rising edge amplitude, high discharge current, high current rising rate and high energy utilization rate. A plurality of Trigatron gas switches can be triggered synchronously.