This guide specifies the test requirements of system commissioning which are applicable to the DC (direct current) distribution network of the voltage level from 750 V to ±50 kV. The guide mainly includes the following aspects: the converter (AC (alternating current)/DC, DC/DC) test; the DC circuit breaker test; the test of active and passive network conversion; the test of the operation characteristics of low voltage DC islanded operation system; the test of feeder power balance system; the coordinated operation test of medium and low voltage DC system; the plug and play system test; the small power system test; the large power system test; the rated load test; the overload test; the short circuit test; and the trial operation.