Abstract: The design principle of magnetic probe for current measurement through plasmas is introduced. A micro magnetic probe device is manufactured to diagnose the load current in Z-pinch experiments on pulsed power facilities, according to the actual structure of wire-array load and the experimental layout. The sensitivity of the probe is calibrated through a load simulator that has the same size as the load used in experiments. Experimental results show that, when the pulsed power facility works at 1.2 MA peak current with 60 ns rise-time, the load current measured by this probe has 12% difference in magnitude and 5 ns difference in peak current time from that measured by accelerator current monitor.