The erecting device of missile launch vehicles will face various external environmental interference factors such as load fluctuations and wind loads during mission execution, resulting in uneven gear loads and affecting the stability of the erecting process. Therefore, research is being conducted on the robust control method of gear load balancing for the vertical device of missile launch vehicles. Analyze the electric driving effect of the erecting system to solve the dynamic expression of the multi-level linkage mechanism of the system, and then complete the motion planning of the missile launching vehicle erecting system under constant power. At this point, based on the environment, the transmission performance is automatically adjusted, and the gear design principle of "small front and large back" is adopted to construct a load adjustment model to optimize the angular acceleration characteristics. On this basis, a speed loop fuzzy PID controller is adopted to dynamically adjust the control strategy for gear characteristics, improve the system"s adaptability to complex working conditions, and avoid local overload by calculating the load balancing margin. A robust control function based on H ∞ norm is used to achieve balanced distribution of mechanical loads between gears. The experimental results show that the proposed method maintains the vertical inclination angle of the launch vehicle below 30 ° after application; The measured values of gear load pressure and rotational linear velocity are closer to the rated maximum value, which can maintain a basically stable changing trend. The proposed method effectively controls the vertical inclination angle, gear load pressure, and rotational linear velocity of the launch vehicle, maximizing the avoidance of external environmental interference on the missile launch vehicle"s vertical system and helping to better solve the problem of uneven gear load.