Abstract: The active laser detection basing on cat's eye effect can detect space optical observation equipments. The laser pulse transmitting in the atmosphere will be broadened to affect the echo waveform distribution from the target, and the echo pulse width is different from the dissimilar reflective target, which can be used to determine detecting target. Based on the photon scattering theory, the pulse broadening caused by the aerosol scattering effect near the ground was analyzed, the calculation physical model was built to resolve cat's eye and diffuse reflection echo pulse broadening and the main factors affecting pulse broadening were provided. The active detecting dynamic tests aiming at the optical cabin loaded on the aeroboat were implemented to validate the physical model, the test results show that the cat's eye and background diffusion reflection echo signals are respectively broadened 20-30 ns and 90 ns after 8～10 km slant path atmospheric transmission. Based on the built physical model, the theoretical pulse broadening on dynamic test condition is accordance with the actual test results, which provides theoretical proof to distinguish and pickup cat's eye echo signal.