The invention provides an integrated intelligent electronic device of a transition layer of an intelligent substation. The device comprises an analog conditioning module, an input and output module, a monitoring management module, a combining unit module, an intelligent terminal module and a power source module, wherein the analog conditioning module is connected with the combining unit module in a unidirectional way, the combining unit module is respectively connected with the intelligent terminal module, the input and output module and the monitoring management module in a bidirectional way, and the power source module is respectively connected with the analog conditioning module, the input and output module, the monitoring management module, the combining unit module and the intelligent terminal module in the unidirectional way. The integrated intelligent electronic device of the transition layer of the intelligent substation has the advantages that the requirement of an IEC61850 protocol is met, the device is mainly used for realizing the integration of equipment in the transition layer of the intelligent substation, the land occupation area of the intelligent substation and the construction, running and maintenance investment are reduced, and the integral benefit of the intelligent substation is improved.