The present application provides a bounded wave strong electromagnetic pulse simulation system. The system includes a high-voltage pulse component and a waveguide antenna connected to the high-voltage pulse component. The end of the waveguide antenna is connected to a load; the high-voltage pulse component includes a DC high-voltage module connected in sequence, a charging resistor, an energy storage capacitor, an air switch, and an energy storage capacitor. The capacitance value of the air switch is adjustable, and the air switch includes a shell, which is provided with a first electrode and a second electrode with a variable discharge gap, and is filled with a working gas with a variable pressure; the DC high voltage module is used to output DC high voltage, and The DC high voltage is compressed into the energy storage capacitor through the charging resistor, and the energy storage capacitor is used to trigger the breakdown of the air switch to form a corresponding voltage pulse, which is transmitted to the load through the waveguide antenna. The amplitude, leading edge, and pulse width of the strong electromagnetic pulse output by the above-mentioned system have a large variation range, a small degree of dispersion, and a high stability of the system.