The invention discloses a current-transformer harmonic wave error measurement system. The system comprises a harmonic wave heavy current generation device, a standard current transformer, a measured current transformer, a harmonic wave current measurement apparatus and an upper computer, wherein the harmonic wave heavy current generation device is used for generating a harmonic wave heavy current; the standard current transformer is used for measuring the harmonic wave heavy current so as to acquire a standard signal; the measured current transformer is used for measuring the harmonic wave heavy current so as to acquire a measured signal; the harmonic wave current measurement apparatus is used for converting the standard signal and the measured signal into a signal to be processed and sending to the upper computer; and the upper computer is used for acquiring a content, a ratio error and a angular difference of a fundamental wave till to N subharmonics. The current-transformer harmonic wave error measurement system provided in the invention can acquire an error caused by a current transformer during harmonic wave measurement so that an influence of an harmonic wave on an error (the ratio error and the angular difference) between the measured signal output by the measured current transformer and the standard signal output by the standard current transformer is obtained, which is convenient for subsequently improving the measured current transformer and accurately measuring the harmonic wave.