In order to realize multi-point current monitoring on power line, a multipoint all-fiber current sensor was described on the principle of time-division multiplexing using ordinary silica fibers and a fiber loop. The multi-channel sensor system was used to share a set of light source, detection equipment and digital signal processing system, which can improve the utilization rate while saving cost. In experiment, a dual-channel fiber current sensor structure was used to measure the current at the same time in the two different points. The direct current of a measurement point ranged from 0 A~600 A and the direct current of another survey points ranged from 0 A~1 500 A. The experimental data is fitted with linear fitting. The results show that the suitable cycle number K is 8 and the current sensitivity of K=8 was approximately 3 to 4 times as high as when K=2. The dual-channel fiber current sensor had good linear responses for both channels between the output signal ΔP and the current I. The channels are independently affected by the current, they require separate calibration.