This paper reports an anti-sideslip line of sight (LOS) method-based path tracking control method for a multi joint snake robot. In order to effectively eliminate the sideslip influence on direction guidance, a finite-time convergent sideslip observer is designed to compensate the LOS guidance law and improve the steering accuracy of the robot. Additionally, considering the external disturbance and state constraints, a barrier Lyapunov function-based backstepping adaptive controller is proposed to ensure the environmental robustness of the robot. In this work, the sideslip and interference are observed accurately, avoiding the imprecise constraint conditions. Finally, the validity and feasibility of the proposed method are proved by theoretical proof and numerical simulation.