The invention discloses an anti-direct-current performance detecting device and method of a current sensor. The anti-direct-current performance detecting device comprises a half wave current source, astandard current transformer and an anti-direct-current performance tester. The half wave current source outputs two paths of positive and negative half waves respectively that are connected in series with primary sides of two detected current sensors once to form two positive and negative half-wave current test loops. The primary side of the standard current transformer is connected in series with the two positive and negative half-wave current test loops to form a full-wave current test loop. The secondary side of the standard current transformer and the secondary sides of the detected current sensors are connected with the anti-direct-current performance tester. The method includes the following steps: step one, determining the type of a standard current transformer; step two, connecting a through-type standard current transformer; step three, connecting a re-turn type standard current transformer; step four, starting an anti-direct-current performance tester; and step five, outputting a current by a half wave current source, detecting the anti-direct-current performance, and recording the detection result. Therefore, problems of zero-crossing dead zone and half-wave current distortion are solved; and the detection efficiency and accuracy are high.