This paper researches the integration of merging unit and intelligent terminals on the bus PT interval. Combined with practical engineering, it gives the product hardware and software architecture diagram, describes in detail the design of analog to combined wisdom of one device applied to PT interval relying on PowerPC MPC8377 core processing chip. This paper gives the hardware and software design solutions, and achieves subscription and publishing GOOSE by a combined wisdom of one device. The switches of PT status monitoring is achieved through the signal of switch collected, and the delivery of SV is implemented through analog acquisition and merger, which can eventually meet the project for merging units and intelligent terminals intensive needs, and saves space and cost and reduces optical port. Experimental results show that the developed bus one device combined wisdom has low cost, powerful function, high performance, and better completes the state monitoring and controlling of PT switch, bus voltage merger and acquisition protocol converter functions. The device can fully meet intelligent substation IEC 61850 communication protocol.