Abstract: The single flake light projectile detecting technology is used for measuring the pro-jectile velocity exactly in hypervelocity impact test that are usually carried out for space debris re-search.For detecting projectiles with diameter less than 1mm,we develope the photoelectric ar-ray projectile detecting technology based on the single flake light projectile detecting technology. The key problem of detecting projectile with diameter less than 1mm is to increase the intensity of detected signal.It could be resolved by increasing the ratio of the projectile diameter to the flake light width.A test device for the photoelectric array detection system is developed and in-stalled at the hypervelocity ballistic range.A series of tests were carried out at the hypervelocity range,which show that the SNR is enhanced and projectile with diameter of 0.6mm was able to be reliably detected with the photoelectric array detection technology.Data analysis shows that the technology can be used for reliably detecting projectile with diameter of 0.1mm.