To implement the national cyber-power strategy，China must build itself into a big power of cyber international law，and participate in an active and deep-going way in the formulation and application of international rules on cyberspace. Because of such factors as the high importance attached by Chinese government to cyber international law and the primary stage of development of cyber international law，China is faced with a rare opportunity to build itself into a big power of cyber international law. Meanwhile，it is also faced with huge challenges posed by the problems and uncertainties in the new field of application of international law in cyberspace and China’s weak foundation of international law. To seize the opportunity and meet the challenges，China should make more efforts in such fields as image building，theoretical research，practical guidance，institutional building and talent cultivation，so as to build itself into a big power of cyber international law，and effectively exercise its discourse power and influence in the formation of relevant international rules.