Flexure hinge has the characteristics of small stroke and high positioning precision and has higher requirement on machining accuracy.Aiming at the three machining errors of flexure hinge key size

through modeling and force analysis

the calculation formula of rotation stiffness of circular flexure hinge considering the machining errors is derived.The stiffness error is calculated by using numerical integration method

and a kind of non-dimensional stiffness error calculation formula is fit out.Meanwhile

the verification on the formula is carried out by using finite element simulation.The stiffness errors of numerical analysis method are compared with and FEA method

the results show that it has good consistency

and a reference for flexure hinge design and machining is provided.