The invention discloses an all-fiber optical current transformer detection system. The all-fiber optical current transformer detection system comprises a sensing optical fiber ring, a light path system, a circuit system and a merging unit; the sensing optical fiber ring is used for acquiring a current signal of a to-be-detected position and generating a light intensity signal carrying data information of a Faraday rotation angle; the light path system is used for transmitting the data information to the circuit system by virtue of the optical fiber; the circuit system is used for receiving data information transmitted by the light path system and converting the data information to a circuit digital signal; the merging unit is used for receiving the circuit digital signal generated by the circuit system and outputting an identification signal. The current transformer adopts a special optical fiber winding way, so that the temperature drift can be effectively inhibited, the influence of the birefringence phenomenon on detection precision of an ordinary optical fiber transformer can be overcome, the birefringence phenomenon is influenced by the temperature, so that the precision drift of the detection precision caused along with the temperature variation exists.