Abstract: In order to solve the key problem of the flexibility of the arrangement of the poison rods and the sealing of the device in the preliminary design of the neutron poison system of the plutonium criticality experiment device, and based on the magnetic suction control method, a preliminary design for the criticality experiment device for the magnetic suction non-contact arrangement of the neutron poison rods is proposed in this paper, which can realize the arrangement scheme of neutron poison rods, with or without rods, with different numbers,different materials, different arrangement, and different heights under the condition of completely sealed and without contact, which can effectively solve the problem of radioactive aerosol sealing in criticality experiments with neutron poison rods in the plutonium solution and insufficient accuracy of changing the arrangement of neutron poison rods. Compared with traditional methods, the scheme has great advantages, and can provide feasible ideas for the detailed design of such experimental devices.