The invention discloses a system and a method for detecting a current and relates to the power metering equipment technology field. The system comprises a current transformer tester. The current transformer tester comprises a host end, a test end and a mobile terminal. The mobile terminal is connected with the host end. The method comprises the steps that based on the current transformer tester and the mobile terminal, the host end of the current transformer tester sends detection data to the mobile terminal; and through the host end and the test end of the current transformer tester, the mobile terminal and the like, working efficiency of detecting a current transformer is improved.