Based on the structural bionic method, the rotary worktable of vertical lathe was optimized. Through fuzzy similarity analysis, the similarity of the bionic prototype and the rotary worktable was obtained, and the rationality of the bionic prototype was verified. According to the bionic prototype, the optimization model was established. Then it was transferred into the Workbench of the ANSYS to be analysed by the finite elements method. Comparing with the prototype, the results indicate that the bionic worktable’s mass reduces 280kg, and the deformation reduced 4.7%. The first five natural frequencies of bionic worktable increased. The results show that the bionic rotary worktable is more reasonable. It offers a new solution to optimize the rotary worktable of various vertical lathes.