The current within imploding multiwire tungsten arrays is measured using micro magnetic probes in the Qiangguang-1 facility at a current of 1.3 MA and rise time of about 70 ns. Difference in current distribution in multiwire arrays between with and without foam cylinder on the array axis is studied. Stable and reliable results are obtained for tungsten wire array Z-pinch with a wire diameter of 4.2 μm and an annular diameter of 12 mm. The results shows that the output of magnetic probe at a radius of 3.2 mm lags about 20 ns behind the discharge current pulse. After that, the ratio of inside current to the total current increases 20% within 20 ns and keeps steady for 30-40 ns. It is found that the foam cylinder has no appreciable influence on the inside current value in the initial stage of implosioin.