Abstract: The connotation of the outer space militarization includes both the conditions of the military use of satellites and the outer space weaponization. Accordingly,different modes should be taken to regulate the outer space militarization under the international law,based on its different conditions. Since the existing international treaty law cannot regulate the outer space militarization sufficiently and effectively,especially cannot ban the outer space weaponization,and the promotion of such international treaty law is also facing quite a few difficulties which cannot be solved in due course,it should be a better route of regulating the outer space militarization under the international law by establishing the rule of customary international law on banning the outer space weaponization. The practices of banning the outer space weaponization have basically met the requirements of the substantial element,namely the state practice,for formulating the customary international law; while the mental element,namely the opinio juris is still far beyond. Withal,the international community should take more active and positive actions to facilitate the establishment of such the rule of customary international law.