To improve the performance and accuracy of automatic guidance system with contact sensor, a guidance control system of tractor with two-level controller was designed for the maize stubble inter-row tracking operation. High level controller using fuzzy control algorithm was developed based on signal analysis of contact sensor. In fuzzy controller, the input was angle of feeler and the output was desired steering angle of front wheel. PID algorithm with nonlinear compensation was adopted as low level controller to implement tractor steering angle control, which took nonlinear of electrohydraulic system into consideration. The control algorithm was simulated with Matlab/Simulink tool and experimented by tractor guidance control system in stubble rows field. The results show that the response and stability of control algorithm are effective in auto-steering of tractor. The guidance accuracy of control system with two-level controller can meet the requirement of inter-row operation by 50mm as maximal track error and 15mm as average track error.