Using the way of laser in centimeter scale space debris removal has been the hot research topic around world. The characteristics of impulse coupling and reducing the speed and de-orbit with space debris induced by laser irradiation are utilized in their removal. According to the two characteristics, four key problems, that were space debris plasma plume induced by laser ablation, measurement of space debris impulse by laser ablation, space debris orbit estimating and laser parameters in space debris removal, were discussed in detail. The concerned technology difficulties, the adopting research methods and the realized ability level were analyzed. Based on the above discussion, it can provide solid basis for its future project realization.