A new technology for oil-line debris detection based on electrostatic induction is developed for nonmetallic materials online monitoring of oil system in engine. The formation mechanism of charging debris and oil-line debris electrostatic monitoring principle in lubrication conditions are researched. The electrostatic signal feature extraction method is studied. Simulated experimental platform has been designed and developed to prove the feasibility of electrostatic monitoring technology. Two types of experiments are carried out. The first one is the injection of charged particles simulating the fault. The second is the sliding contact of friction and wear on modified pin-on-disc tribometer. A sensor with two ring-shaped probes is used to monitor the moving charged debris in insulation oil system. The results show that the oil-line debris electrostatic monitoring sensor can monitor the charged particles of various metallic and nonmetallic materials; inductive voltage is relevant to the debris size; shape of the inductive voltage is relevant to the debris charging characteristics; the sensor can online monitor the lubrication contact nonmetallic friction pair wear conditions.