A current detection device applied to a multi-core conducting wire comprises a carrier, magnetic sensors and a processor wherein the processor is connected to the magnetic sensors. The carrier has an accommodating channel for accommodating the multi-core conducting wire. The magnetic sensors are disposed at the carrier, surround the accommodating channel, equally share 360 degree of the peripheral of the accommodating channel, and are configured to measure an alternating magnetic field of the multi-core conducting wire to respectively obtain magnetic field measured values, wherein each of the magnetic sensors corresponds to a respective one of the magnetic field measured values. The processor stores a current decoupling model, and is configured to obtain the magnetic field measured values from the magnetic sensors and to calculate a current value of each core wire of the multi-core conducting wire according to the current decoupling model and the magnetic field measured values.