The invention discloses an alternating current high-current sensor, which comprises an annular sensor and an integral processing circuit, wherein the annular sensor is n layers of annular PCB boards, the cross section of the annular sensor is provided with f n/2 spiral coils, and the adjacent spiral coils are orderly and serially connected; the spiral coils consist of conducting wires on various layers and via holes among the layers, and are connected to a bottom layer through the conducting wires; and the spiral coils are equidistantly and evenly distributed along the circumferential direction of a circular ring, an innermost ring or an outermost ring is reversely printed with a circle of conducting wires along the spiral coils, the conducting wires jointly form two-end output with the spiral coils, and the output is connected to the integral processing circuit. The alternating current high-current sensor is sensitive to the measured current and the change of the measured current, ensures that the increase of the measured current can not saturate, has good linearity and convenient installation and use, and can also effectively eliminate the influence of adjacent current at the same time; and the alternating current high-current sensor can be singly used, or a plurality of alternating current high-current sensors are serially connected to use. The alternating current high-current sensor is suitable for the measurement of alternating current high current, and can simultaneously meet the requirement of the measurement and protection of an electric power system.