The invention discloses a current step response test standard source for a direct current measuring device, which comprises an upper computer, a standard source control module, a direct current constant current source power module, an energy storage inductor, a first loop IGBT switch, a second loop IGBT switch, an IGBT driving unit and an IGBT RCD buffer circuit, a large current freewheel diode. The test standard source can realize the step response test on the direct current measuring device according to the requirements of a national standard, and the method for switching the constant current source output current loop through two groups of IGBT switches solves the problem that the rise time of the output current of a direct current steady current source is slow, the pulse power type impact current source output current attenuation is fast, therefore, the tow cannot be used as the current step response test standard source of the direct current measuring device, the dual requirementsof the step response test to the standard source, microsecond level rise time and millisecond level duration time, are realized, and important parameters, such as step current peak value, current duration time and the like, can be adjusted and configured accurately and flexibly.