Abstract: In order to provide an experimental platform for research on ultra-wideband electromagnetic pulse effect mechanism and protection technology, a high-power ultra-wideband electromagnetic pulse radiation system based on impulse radiation antenna (IRA) is developed. The radiation system is composed of a differential high-voltage pulsed source, a peaking switch, an IRA, and a dielectric lens. In the design, the differential pulsed source is realized by the pulse source based on hydrogen thyristor driving the pulsed transformer with secondary side center tapped. The designed compact peaking switch has a total height of only 1 cm and a switch gap of 1 mm. It can be embedded at the feeding point of IRA antenna, and the maximum working pressure of the switch can reach 3 MPa. Based on the Fresnel's theorem, a dielectric lens is designed to correct the influence of high-voltage gas switch and insulating transformer oil on the radiation center of IRA and improve the radiating performance of the antenna. The radiation system can adjust its radiation power by changing the air pressure and charging voltage of the gas switch. The test results show that the main technical parameters of the radiation system are as follows: in the time domain, the rising edge of the radiation electric field pulse is about 330 ps, the amplitude is about ±8 kV/m, the far-field effective potential is up to 44 kV, and the radiation power is adjustable; In the frequency domain, the center frequency of the radiating field is 400 MHz, the frequency band defined based on the energy norm ratio is 80 MHz~1 GHz, and the band ratio is about 12.5, which means the percentage bandwidth is 170.4%. The radiation system can be used as a test platform for the research of UWB electromagnetic pulse effect threshold and protection technology.