Abstract: The flash radiation test system was utilized to conduct a series of tests in order to investigate the characteristics of flash radiation generated under hypervelocity impact conditions. The aim is to analyze how the three factors of impact velocity, projectile diameter and target chamber vacuum affect the frequency and time domain characteristics of flash radiation. It is found that the flash spectrum consists of a fixed wavelength line spectrum and a continuous spectrum. As the impact velocity increases, the projectile diameter increases, and the ambient pressure of the target chamber decreases, the integrated intensity of the spectrum increases significantly, although the impact condition has relatively little effect on the intensity of the continuous radiation; moreover, the increase of the impact velocity leads to the prolongation of the duration of the strong flash, but at the same time, the decay rate of the flash temperature is also accelerated; under the similar conditions of the impact velocity and the ambient pressure, the effect of the projectile diameter on the flash duration is not significant; the effect of the projectile diameter on the flash duration is not significant; and the effect of the target chamber vacuum is not significant. Under similar conditions of impact velocity and ambient pressure, the effect of projectile diameter on flash duration is not significant; the decrease of ambient pressure in the target chamber leads to the prolongation of the duration of the strong flash and a slower decay of the flash intensity. This study provides important experimental data and theoretical basis for the understanding of the flash radiation phenomenon during hypervelocity impact.