The invention discloses a current transformer device for high-precision current-voltage conversion. The current transformer device comprises a core, a primary winding and a secondary winding and is characterized in that the primary winding is of a multi-tap structure and at least comprises a first tap and a second tap, a primary current corresponding to the first tap is 1A, a primary current corresponding to the second tap is 5A, a secondary current corresponding to the output of the secondary winding is 50mA, a resistor R1 and a resistor R2 which are connected in series are arranged between the secondary winding and are identical, and a part between the R1 and the R2 is grounded. According to the device, a high current of 5A or 1A is converted into a 1.25V voltage signal, which facilitates digital signal processing, separately through a 0.005-level current transformer and the two resistors which have the characteristics of 0.005 high-precision and 1ppM ultralow temperature coefficient, so that compared with the traditional resistance sample current-voltage converter, the device has the advantages that a temperature drift phenomenon cannot occur, and the final conversion precision can reach a 0.01 level.