As the lack of laboratory testing methods for dynamic load metering error of digital electric energy meter used in smart substation, a kind of dynamic error of digital electric energy meter test equipment, which adopts OOK dynamic test signal model, is developed in this paper. First, OOK dynamic test signal model is introduced; secondly, the overall hardware design scheme of equipment is put forward; Based on the scheme, this paper proposed the methods of OOK signal generation, and IEC61850-9 protocol SMV group packing. Final test shows the signal waveform generated by the device can exactly meet the requirements of the OOK model, and shows the equipment can effectively test the dynamic error of digital electric energy meter.