The invention discloses a waterproof rubber device of an open type CT power pickup device. The waterproof rubber device comprises a coil, a magnet ring, seal rings, a liner and a shell, wherein the shell is located at the outmost portion of the CT power pickup device, the liner forms an inner ring shell of the CT power pickup device and can hold a wire, the magnet ring serving as the working part of the CT power pickup device is arranged between the shell and the liner, and an outer ring of the magnet ring is provided with the seal rings for protecting the end face of the magnet ring. An existing mature open type CT power pickup magnet ring is used as a basis and has the advantages of being good in protective property, small in size, good in waterproofness and the like. On the basis of not affecting original excellent performance of the CT power pickup magnet ring, the design of the end face seal rings is added, and the service life of power pickup CT is prolonged.