Partial discharge is one of the important indexes to evaluate the insulation state of medium and high voltage equipment. Ytc9100 handheld ground wave partial discharge detector / cloud locator is used for partial discharge measurement and positioning of medium and low voltage switchgear (3 ~ 66kV). The instrument adopts transient ground voltage sensor to detect and locate the insulation internal discharge of the switchgear. Combined with advanced cloud computing and intelligent modeling technology, it realizes the measurement, recording, transmission, storage, analysis and exchange of partial discharge signals, which provides strong technical support for the on-site measurement of partial discharge. The surveyors use ytc9100 to collect partial discharge information, and can intelligently diagnose the insulation state of the detection equipment in real time through cloud computing.