In the process of evolving from the traditional circuit-switched network to the soft switch-based scheduling switching network, each pilot region of the State Grid Corporation has a lack of experience in comprehensive scheduling business interoperability between scheduling systems from different manufacturers of IP network or TDM + IP hybrid network. This paper proposes a test scheme to evaluate the interconnection between the dispatching systems of mainstream manufacturers in a laboratory environment. We aim at solving the problem of scheduling business interoperability that existed in the testing process, and providing specific and feasible standards for the interoperability between the scheduling systems of different manufacturers. It is shown that the interoperability issues between scheduling systems are well solved after the manufacturers adopt the standards, providing technical support for accelerating the evolution process of power dispatching network.