A generator rotor insulation monitoring brush device comprises a lever device; the lever device is fixed to a unit shell through a lever shaft and bearings on the two sides; a groove is formed in oneend of the lever device to contain a carbon brush; a carbon brush leading-out wire penetrates through the lever device, is led out from the lower portion of the lever device and is finally connected to an aviation plug; the other end of the lever device is connected with an iron core; the iron core and the lever devices are movably connected; the iron core penetrates through a spring and then is inserted into an electromagnetic coil; the spring is located between the electromagnetic coil and the lever device; and when the iron core is subjected to downward electromagnetic attraction after theelectromagnetic coil is powered on, the spring is compressed, the iron core drives the lever device to move downwards, and the carbon brush end is lifted.