The invention belongs to the field of containers used for storing materials, and particularly relates to a treating device for seeds. The treating device includes a preservation barrel and a rack, thepreservation barrel is internally provided with a desiccant cavity and a seed storage cavity and further internally and fixedly provided with a hollow sliding rod, the rack is fixedly provided with amotor, an air cylinder, an airbag and a piston cylinder, the motor is connected to the preservation barrel, and a cam is coaxially arranged on an output shaft; the air cylinder is communicated with the airbag through an air inlet pipe, a check valve is arranged on the air inlet pipe, the airbag is communicated with the piston cylinder through an air outlet pipe, and a pressure valve is arranged on the air outlet pipe; the piston cylinder is internally and slidingly connected with a sliding block and a magnet, the sliding block and the magnet are both connected with the inner wall of the piston cylinder through springs, the hollow sliding rod is communicated with the piston cylinder, and a steel ball is arranged in the desiccant cavity. By adopting the treating device, the purposes of preserving the seeds, improving the drying effect and providing more convenience for taking and placing are achieved, and the treating device is used for preservation of the crop seeds.