After the CMOS detector in imaging system is damaged by laser, the corresponding cat eye echo will change. The changes of the cat eye echo are researched experimentally. With the increase of laser power for damage, the microlens of the CMOS detector decomposes gradually, and disappeares at last. The surface of the detector turns into a two-dimensional grating composed of aluminum film and sensitive area in the end. The array spots in the cat eye echo-wave pattern goes through messy and then turns back arrays. The surface morphology of the damaged microlens is modeled by a Gaussian random surface in simulation, and the changes of the echo-wave pattern are calculated with the damage of the microlens. The theoretical results are consistent with the experimental phenomena.