Abstract: Aiming at problem of caterpillar tractor can′t use automatic navigation system for wheeled vehicles directly，a control method which setting on a conversion model for track speed，virtual driving speed and virtual steering angle was proposed.Through analysis between two-wheel model of wheeled vehicles neutral steering and steering kinematics model of tracked vehicle，expressions of track speed，virtual driving speed and virtual steering angle was derived，feedback control for autopilot systems was completed.Real vehicle turning experiment was carried to collect data and validate conversion model proposed.Results showed that theoretical values were in good agreement with actual reference values under the model，steering control method was feasible.