Abstract: Navigation control parameters tuning is a challenge for modern automatic guidance control,so as to keep the machine on the desired path or to approach the desired path as quickly as possible without too much overshooting.The John Deere’s AutoTrac is typical navigation system with a low-cost auto steering system incorporating a GPS receiver and built-in algorithm to control the vehicle’s steering wheel.To maintain the navigation performance of AutoTrac in different working conditions like soil properties and operation speed, the algorithm in the controller defines as many as nine parameters, a difficult and time-consuming task for normal operators.A universal navigation control parameters tuning method was proposed base on Taguchi method and orthogonal experiment.Verify experiments were carried out on John Deere’s AutoTrac with XUV825i gator vehicle.Tests were done with RTK signal under straight line navigation mode in different soil properties and operation speeds.Optimal range of key AutoTrac navigation control parameters, such as steering sensitivity, line sensitivity tracking and line sensitivity heading at steady-state, were found via first course tuning and then fine tuning.Tests results indicated that soil properties and operation speed had influence on navigation accuracy in stable.Moreover, the proposed method was proved to be efficient in tuning navigation control parameters.It was proved that the optimal range of navigation control parameters was suitable for normal agriculture environment.The proposed method was suitable for other automatic navigation system and it paved the way for further development of adaptive control system of navigation control parameters in autonomous navigation systems.