In order to precisely examine the feature of impulse vector driven by high-energy pulsed laser irradiating space debris, on the basis of assuming linear variations of ablation threshold coefficient, incident laser fluence, and impulse coupling coefficient with the on-target laser fluence, a treatment scheme is proposed to elaborately describe the impulse coupling coefficient, and the numerical calculation method of impulse vector is further improved. By taking cylinder debris as an example and referring to simulation experiment, the effect of impulse coupling coefficient on impulse vector is analyzed from different perspectives, and it is pointed out that moderately increasing the incident laser fluence can significantly increase the impulse vector.