Abstract: When a shaker of six degrees of freedom (6-DOF) is applied in a high frequency vibration test, the table of the shaker might easily be in the state of resonance, which will greatly influence the accuracy of the test results. To make the first-order natural frequency of the 6-DOF shaker's table higher than the working frequency and reduce its mass, an optimization approach for the table based on the two-level multi-point approximation method is proposed. Firstly, the finite element model of the table is established, including the boundary conditions according to the actual working situation. Then, the structure model's shell and beam properties and the radius of the shape are taken as the design variables, with the constraint of the first-order natural frequency and the static strength, a structure optimization model is established to minimize the mass. In the optimum solution, the two-level multi-point approximation method and the man-machine interactive method are, respectively, adopted in the size and shape optimizations. Based on the results after optimization, a prototype including the table structure is designed and manufactured. The structure can meet the lightweight design requirement and is used in the vibration test, thus this optimization approach is validated.