Aiming at the requirement of on-site partial discharge ultra-high frequency (UHF) signal detection, to solve the problem of large size of traditional Archimedes spiral antenna for partial discharge detection, a miniaturized Archimedes wide-band planar spiral antenna is designed by using a new sine wave loading mode in which the amplitude increases linearly with the amplitude angle. The radiation principle of Archimedes plane spiral antenna is analyzed, the structure parameters of miniaturized antenna are determined, and the port parameters and radiation performance of antenna are studied by simulation and measurement. The results indicate that the antenna has ultra wide band characteristics, the return loss is less than-10 dB in the frequency band of 700~3 000 MHz, and the maximum gain is not less than 5 dB in the frequency band of 500~3 000 MHz, which meets the requirements of partial discharge detection antenna. In the laboratory, the partial discharge test is simulated and the test performance of the miniaturized antenna is compared with that of the other two large gain antennas, the results show that the designed antenna has good detection performance and the advantage of small size is more suitable for partial discharge field detection of electrical equipment with complex structure.