Wide area protection using information from multi-location has now become a hot spot in the relay protection domain. The publication of IEC 61850 series standard makes the implementation of wide area protection possible. By taking the wide area current differential protection IED as an example， using the hierarchical function structure， a uniform object model and an abstract communication service interface of IEC 61850 as reference， the modeling of wide area current differential protection IED is given and the new logic node of the protection is expanded， realizing the interoperability between IEDs. The hardware of wide area current differential protection IED is designed while plug-in hardware module is adopted to constitute IED. The mapping relationship between the logical device and plug-in hardware module is also depicted.