In order to evaluate the imaging quality of a high-repetition-rate system in each gated slice and provide fundamental elements for the study of pulse allocation strategy, a theoretical model describing the signal transmission process of the high-repetition-rate system is established based on the Jaffe-McGlamery model, and the factors of image degradation are analyzed. Specifically, an image quality evaluation model of the high-repetition-rate system is proposed herein. Experimentally, a pulsed laser having a repetition rate of 4 kHz is used to image a black-and-white stripe target. Results show that measured values of the experimental image fit well with the calculated values of the model on a linear range from the beginning of the target imaging to the occurrence of saturation, with an estimated error not exceeding 10%.