To solve the problem of few PD defects detected by narrowband acquisition, it is necessary to study the active integrated sensor system with wide dynamic range. In this paper, according to the attenuation analysis of local electromagnetic propagation in GIS under coaxial waveguide model and HFSS simulation, it is found that a dynamic range of at least 40 dB is required for the effective detection of PD signal in long GIS. Secondly, through comparative analysis, the dynamic range of the system can be increased by logarithmic domain transformation, and the butterfly antenna with the optimized size is selected as the antenna for partial discharge detection. The standing wave ratio of the butterfly antenna is less than 2 in the frequency range of 730 MHz~ 1.05 GHz. Finally, a wide dynamic range of frequency-reduction analog circuit is designed, and logarithmic detection technology is developed for GIS partial discharge detection. This paper realized the antenna, detection circuit, signal conditioning and transmission highly integrated UHF local discharge detection sensor system. It not only has excellent signal-to-noise ratio but also greatly reduces the cost of the whole collection system, which has practical significance for PD detection and accurate operation and maintenance.