A trigger device of pulsed power facility is introduced in this paper. The trigger device is composed of Marx generate, power supply, trigger, and et al. The principle of Marx generate (in the paper) is outlined. Equivalent circuit of charging is analyzed, and the waves of charging voltage and current are respectively simulated. Then equivalent circuit of discharging is analyzed, and the wave of output voltage is simulated. The paper proved that simulation wave of output voltage is nearly consistent with the wave of output voltage through experiment with the trigger device. The primary specifications of the trigger device are as following: output voltage amplitude is 30 kV and the rise time of the pulse voltage is less than 20 ns.