Abstract: Simulative experiments on the ground were carried out to measure the radiation by chemical explosion of aerospace explosives in stage separation and evaluate the impaction on the electronics in the rocket. Electromagnetic pulses by different explosives were captured by a rod antenna and measured by a real time analyzer. The results show that radiation increases as the energy of the explosion. When using a mild linear shaped charge,considerable pulses were recorded in dozens of milliseconds after the separation, with the frequencies around megahertz and magnitude about several V/m on single frequency. Electromagnetic environment inside and outside the rocket were recorded and compared by simple dipoles, and current pulses induced on the circuits inside the rocket were also measured. The conclusion could direct the anti-interference design on the inner electronics of launch vehicle.