In order to effectively detect the faulty insulator on high-voltage transmission line

and reduce the laborintensity

this paper firstly analyzes the electric field distribution around the insulator string

and verifies the feasibili-ty of the faulty insulator detection based on the electric field distribution principle using Ansys software. Then the de-tecting principle of the automatic detection device for the deteriorated insulator is briefly described in this paper. Con-sidering the detection device may affect the electric field distribution

the electric field distribution along insulator stringwith detection device or not is simulated in Ansys software. The simulation results show that the existence of the de-tection device has no influence on the judgment of the deteriorated insulator. Finally

the insulator detection tests ofthe insulator string with zero-value insulator or conductive defects are carried out in the laboratory and in the field.The results show that the device based on the electric field method can accurately identify the deteriorated insulator.