Aiming at the problems of low accuracy and easy to cause resonance in the work of the flat sand system, the topology optimization design of the cantilever beam structure of the flat sand system is carried out in this paper. Starting from the internal material layout of the cantilever beam, taking the distortion energy density of the material as the optimization goal, the alterable density method was used to optimize the topology of the cantilever beam in the ABAQUS software, and the most reasonable material distribution is obtained. The optimization results show that when the applied load is 400 N required by the working conditions, the displacement of the front end of the cantilever beam decreased from 4.205 to 1.447 mm, which meets the requirements of the working conditions after optimization. The maximum stress decreased from 20.04 to 6.824 MPa. When the mass of the cantilever beam decreases by 41.4%, the 1 st order natural frequencies of the cantilever beam increased by 2.481 Hz, which is far away from the external excitation frequencies, and the dynamic performance of the cantilever beam is improved. The maximum displacement of the model after topological optimization is verified to meet the requirements of the working condition through the angle change test, which effectively improves the overall utilization of materials and provides a theoretical basis for the design of the flat sand system.