Abstract: With the rapid development of information technology, cyberspace operations play a more and more important role in joint operations, and the effectiveness evaluation of cyberspace operations has become an urgent problem to be solved. In the context of joint operations, the effectiveness of cyberspace operations is no longer just the offensive and defensive effects in cyberspace, but the overall impact on the system level. Compared with traditional physical warfare, the effectiveness of cyberspace warfare has two new mechanisms: one is that the core of its effectiveness is control and influence, and the other is that it can create a short “superiority window ” . Based on this, the influence of cyberspace operations on the information superiority of the system of systems is considered, an evaluation index of operational capability of networked systems called operational potential is proposed, and meanwhile a visualization metric method for the superiority window is put forward. Finally, through experiments, the feasibility of evaluating the effectiveness of cyberspace operations with the operational potential and superiority window is verified, and the beneficial conclusions of the timing and manner of the application of cyberspace operations in joint operations are obtained. The evaluation method of cyberspace combat effectiveness can quantitatively and visually evaluate the effectiveness of cyberspace operation in the context of system-of-systems confrontation, and can guide the application of cyberspace operation in joint operations.