The present invention discloses a proportional direct-current superposition method-based current transformer anti-direct current performance detection method. A standard current transformer, two analog-to-digital conversion circuits, a central processing unit, a display, a direct current source, an alternating current source and two sampling resistors are adopted; the alternating current source and the direct current source output alternating current and direct current respectively according to a set ratio; the primary loop of the standard current transformer is connected in series with the primary loop of a test current transformer through an alternating current loop; a direct current loop passes through the magnetic core of the test current transformer, so as to form a primary loop; the secondary current of the standard current transformer passes through the sampling resistor R0, so that U0 can be obtained; the secondary current of the test current transformer passes through the sampling resistor RX, so that UX can be obtained; the central processing unit controls the two analog-to-digital conversion circuits through a data bus, so as to make the two analog-to-digital conversion circuits carry out synchronous sampling on U0 and UX; calculation is carried out; a calculation result is displayed through the display; and therefore, the anti-direct current performance of the test current transformer can be realized. With the proportional direct-current superposition method-based current transformer anti-direct current performance detection method of the invention adopted, the problem of realizing quantitative analysis of a direct current component in the anti-direct current performance detection detecting process of a current transformer can be solved.