The invention relates to a self-discharging characteristic evaluation method for a redox flow cell system. The self-discharging characteristic evaluation method comprises the steps of discharging the redox flow cell system until a discharging cut-off condition is reached, then charging the system until a charging cut-off condition is reached, and recording charging capacity QC; in a hot stand-by state, enabling the redox flow cell system to operate at an operating management mode for a certain time, and recording the operating time T-D; discharging the redox flow cell system until the discharging cut-off condition is reached, and recording the residual battery capacity QR; and calculating and analyzing the characteristic parameters of the redox flow cell system, and performing evaluation through self-discharging evaluation index. By adoption of the technical scheme, the self-discharging characteristic can be evaluated in a targeted manner rapidly and accurately from each level of the redox flow cell system.