Abstract: It is a contradiction between the concept of the common interests of mankind and the technical differential space rent which is pursued by each state in the exploitation of outer space that is promoting the development of security situation in outer space. Arms control, as a way of seeking security through international cooperation, is a fundamental way to resolve this contradiction. At the same time, from the perspective of realistic constructivism, the substance of the international legal regime to prevent the weaponization in outer space is social construction of all kinds of powers in the process of each state participating in rational games of interests-powers. An analysis of the types and interactions of powers can not only help to master the characteristics of the international legal regime to prevent the weaponization in outer space but also probe into the right way of realistic construction of the international legal regime to prevent the weaponization in outer space.