In the research of space debris impact induced discharge the measurements of the density and temperature of the impact plasma are very important and difficult. Spectrum analysis is the best method of measuring the density and temperature of hypervelocity impact induced plasma. This method has been successfully used for detecting the density of the plasma produced by hypervelocity particles with diameters larger than 1 mm. In this paper, we present a method of detecting the light flash that is produced by the hypervelocity impact of 200 μm particles which is the foundation for the spectrum analysis method. The characteristics of the light flash of the impact and the impact induced discharge are also discussed.