The invention provides a device for removing sulfate radicals in spent fuel pool water. The device comprises a double-layer resin bed and a pump, wherein the pump is used for communicating the double-layer resin bed with a spent fuel pool, and is configured to pump water in the spent fuel pool into the double-layer resin bed. According to the device and the method for removing the sulfate radicalsin the spent fuel pool water provided by the invention, the problem that sulfate radical ions are increased in the operation of a purification bed of the spent fuel pool is solved, simultaneously, the problem that the resin is oxidized by hydrogen peroxide is avoided, the water quality of a loop is improved, the decline of the performance of the positive resin and the early saturation of negativeresin are avoided, the service life of the resin bed is finally prolonged, and the water quality of the spent fuel pool is improved.