In order to solve a series of problems of traditional thyristor trigger device, a new thyristor trigger device controlled by PWM pulse was designed. The device consisted of five parted of two-way thyristor electronic switches, load, zero pulse generation and DC voltage unit, trigger signal generating unit and control signal given unit. Taking the bidirectional thyristor as two-way electronic switch, CMOS not gate as the core of phase shift control unit and its threshold voltage directly as the trigger reference voltage, applied PWM signal to phase shift control. The experimental results show that the device has strong anti-interference ability, good phase shift control linearity, which is low cost, small volume and works reliably.