A soft x-ray streak camera system based on the conversion of fast scintillator has been developed to diagnose 10-MA Z-pinch implosions on the Primary Test Stand facility. The streak camera system is used to measure the continuous time history of the 0.2–10 keV x-ray emission from pinch plasmas and proved to be free from the intense electromagnetic environment effectively during the discharge of the Primary Test Stand. The spatial resolution of the streak camera system is estimated to be less than 120 μm, and its temporal resolution has been calibrated to be about 1 ns. X-ray streak images of aluminum wire-array plasmas have been obtained successfully in experiments, and the nonuniformity of the x-ray emission along the axial direction has been observed.