A modeling method for steering resistance moment in small tracked robot is studied. First of all, Classical steering resistance torque modeling with uniform resistance is studied in low speed and high speed. Then the steering resistance torque modeling while lateral resistance and the pressure are linearly distributed is proposed. After that steering resistance moment modeling based on the stress-strain theory is used to describe the robot's steering resistance above different soil. Among them, the lateral resistance is nonlinear distribution. The driving experiments in three different vehicle terramechanics models are simulated and analyzed. Steering resistance moment modeling based on the stress-strain theory is closer to the actual working state of the robot. This modeling method for steering resistance moment has advantage on optimization and study in and control algorithm.