The invention provides a dielectric response non-outage monitoring system and method of an oil paper insulating bushing. The system comprises a high-voltage bus, a high-voltage bushing, a transformer,a voltage transformer, a current transformer, and a data collection and processing unit; a top end of the high-voltage bushing is connected with the high-voltage bus, and a bottom end of the high-voltage bushing is mounted on the transformer; the voltage transformer is arranged at a line inlet side of the high-voltage bus, one end of the voltage transformer is connected with the high-voltage bus,and the other end is connected with the data collection and processing unit; the current transformer is arranged in a bushing end screen of the high-voltage bushing, an end screen lead line of the high voltage bushing is arranged by penetrating a coil of the current transformer, and an output end of the current transformer is connected with the data collection and processing unit. A harmonic voltage signal in the system is directly used as an excitation source of a dielectric response test without injecting an excitation signal from the external, the system has the advantages of being rich inmeasurement information, high in test precision, safe and reliable, and can realize real-time diagnosis without power outage.