The invention discloses a comprehensive monitoring device for the partial discharge of an oil immersed transformer. The comprehensive monitoring device is characterized in that the oil immersed transformer is electrically connected with a monitoring computer USB interface through a partial discharge infrared monitoring instrument, the oil immersed transformer is electrically connected with the monitoring computer USB interface through a partial discharge ultrasonic monitoring instrument, and the oil immersed transformer is electrically connected with the monitoring computer USB interface through an oil chromatography analysis instrument; the oil immersed transformer is electrically connected with the monitoring computer USB interface through a running data acquirer of the oil immersed transformer, and the monitoring computer is electrically connected with a partial discharge monitoring historical data computer through a network interface RJ45. The invention further provides a monitoring method. Because the monitoring device is realized in combination with computer value simulation software and on the basis of conventional parameters in the running of the oil immersed transformer, and a conventional monitoring technology, effective partial discharge monitoring for the running process of the oil immersed transformer can be ensured; the capacity of resisting risks is enhanced, and a power grid is safe and stable in running. The method is scientific, reasonable and effective.