The utility model discloses an intrusion type power distribution apparatus partial discharge on-line monitoring device including a sensing unit and a monitoring host, the sensing unit is composed of a transient ground voltage sensing unit and an ultrasonic sensing unit, the monitoring host comprises a signal conditioning unit, a signal processing unit, a display unit, an ultrasonic signal monitoring unit, and a power supply unit, the transient ground voltage sensing unit and the ultrasonic sensing unit are respectively connected with the plurality of input ends of the signal conditioning unit, the plurality of output ends of the signal conditioning unit are respectively connected with the signal processing unit and the ultrasonic signal monitoring unit, the output end of the signal processing unit is connected with the display unit, the power supply unit is respectively connected with the signal conditioning unit, the signal processing unit, the display unit, and the ultrasonic signal monitoring unit to supply work power, and the sensing unit acquires sensing signals and the monitoring host receives the detection signals of the sensing unit.