The post-hole convolute (PHC),which is used to transport and combine the pulse power flux,is a key component in huge pulsed power generators.Current loss at the PHC is a challenging problem for researchers.To explore a method of reducing the current loss,a single-hole PHC was designed for experiments on the current loss on the Qiang Guang I generator.The experimental results showed that the current loss at the single-hole PHC is related to the distance l between the vicinity of the cathode hole and the surface of the downstream side of the post.Meanwhile,a single-hole PHC with a blob cathode hole transmitted current more effectively than the PHC with a circle cathode hole.The relative current loss at the single-hole PHC with the cathode coated with gold foil was about 30％-50％ of that with the cathode coated with nickel and titanium foil.The gap closing speed was also obtained from the current waveforms in the experiments.The speed was 5.74-14.52 cm μs-1 which was different from the classical plasma expansion velocity of 3 cm μs-1.