Abstract: The new US Space Defense Strategy further increases the risk of weaponization and arms race in outer space, and poses a serious threat to the peaceful use of outer space, thus bringing serious challenges to the international governance of outer space security. This has fully exposed the limitations of current treaties on the prevention of weaponization and arms race in outer space and the difficulties for the soft law of outer space to play an effective regulatory role because of the lack of coercive force. Therefore, it is urgent to develop new international rules on outer space arms control. However, the development of new rules faces three predicaments. The first is the "soft law" of outer space rules, the second is the competition between "hard law" and "soft law", and the third is the disorderly development of "soft law". Only by getting rid of these predicaments can we speed up the formation of new rules, and the way out is to use a two-way coordinated development approach to international rules on outer space arms control. That means it is necessary not only to conform to the spirit of the Charter of the United Nations and the Outer Space Treaty on the peaceful use of outer space, but also to respect the resolutions on outer space arms control reached with the United Nations as the main platform, so as to build a new model for the development of international rules on outer space arms control which is based on "hard law" with the coordination between "hard law" and "soft law".