Abstract: For a novel 2-DoF(degree of freedom) high-speed parallel manipulator,optimal design of sectional parameters is carried out,and the optimal objectives are the dynamic performances of the system at the level of elastodynamics.First,the finite element method is applied to obtaining the elastodynamic equations of the system.Second,the sensitivity of the first order natural frequency with respect to sectional parameters is analyzed to determine the design variables.Finally,two methods of optimal design are proposed to optimize the system.The results show that the methods can meet the needs of design.