The complexity of the mechanical properties of stratospheric airships and their large inertia make the path following control problem particularly challenging. This paper first establishes a 6-DOF model of the airship, then uses a PD controller to control the yaw angle of the airship. Based on line-of-sight (LOS) guidance law, we propose a method of longitudinal deviation compensation to optimize the reference yaw angle of the airship. By performing this method on the original LOS algorithm, the actual longitudinal deviation value is replaced with the calculated value. The value of compensation coefficient k determines the degree of compensation, and the optimal value of k varies during airship flight, which can be derived from experimentation. By adjusting the value of the compensation coefficient k in real-time, the longitudinal deviation between the airship position and the target path can quickly converge to zero. Simulation results demonstrate that compared to the traditional LOS method, this method can expedite the disappearance of the airship's deviation from its expected path, reduce average longitudinal deviation, and minimize flight distance and flight time.