The utility model discloses a device for monitoring insulators through an optical electric field sensor. An LED light source of the device is connected with one end of a single mode optical fiber, an output shaft of a motor is connected with a gear, one end of an insulating cylinder is provided with a driving gear, the gear is engaged with the driving gear, a mounting through hole is formed in an optical sensing head, the other end of the insulating cylinder is threaded in the mounting through hole and fixedly connected with the mounting through hole, the other end of the single mode optical fiber is connected with a signal input end of an optical fiber receiving module, a signal output end of the optical fiber receiving module is connected with a signal input end of a demodulator, and a signal output end of the demodulator is connected with a data communication end of a computer. The device cannot cause electric field distortion when judging deterioration degree of the insulators, is not affected by temperature and humidity, has the advantages of simple operation, high accuracy, high stability and the like, and can greatly improve the detection efficiency of degenerated insulators.