Abstract: In order to yield a space normal force suitable for guidance, the ideal roll motion of an axisymmetric vehicle should be of no static error. Based on the optimization theory for large systems, an optimization model for controllable nonlinear roll motion is established in this paper by coupling the moments and kinematics. The influences of the nonlinear coupling and the autopilot nonlinearity upon rolling static error is analysed comprehensively. By optimizing the multidimensional parameters such as aerodynamic, flight and autopilot ones using a simplex method, the optimal roll motion with practically zero static error can be obtained. A demonstration example on the optimization is given.