Abstract: Currently, international space law system mainly regulated mitigation measures against space debris, but there is no consolidated regulation concerns active debris removal(ADR) measure which could reduce the quantity of space debris dramatically. For the reason of legislative deficiency of legal concept, ownership and jurisdiction of space debris, space-based active removal of space debris might be defined as space military activity, and then rise conflicts regard outer space militarization and legitimate conflicts regard violation of peaceful uses of outer space principle and prohibition of use of force principle. Clarifying the boundary of demilitarization of space-based ADR will contribute to determination of the legal nature of ADR for international community. By analyzing current international space treaties indicated that space debris has its legal feature which would cause "potential harmful interference". It will have negative effect on regular space activities. So, ADR measure shall follow the basic principle as "elimination of hazards to space activities caused by space debris". Any space debris removal conducted under this principle shall not be deemed as outer space militarization or illegal use of force.