Abstract: Laser space debris removal has been the hot research topic around the world. Impulse coupling introduced by high-energy pulsed laser acted on debris is the bedrock and key to achieve debris removal. To study the impulse coupling effects, the aluminium alloy-ball-hanged single pendulum movement were recorded, pushed by ns-pulsed and ms-pulsed laser respectively, with high speed camera. By analyzing the impulse coupling generation theory, difference of the impulse coupling coefficient and the variety rate between the two mode lasers was summarized. Especially, a conclusion was drew that ms-pulsed laser could produce much more unit area impulse coupling than ns-pulsed laser, available for space debris removal. Moreover, compound ms-pulsed laser with ns-pulsed laser could increase the coupling efficiency and obtain higher impulse coupling. The study in this paper indicates a new idea for laser space debris removal, which have strong directive meaning.