To calculate, analyze, and predict the rotation angle during the deceleration and braking process of large remote-controlled excavators, this article established a spatial coordinate system based on a simplified model of a hydraulic excavator’s upper structure. Using the D-H parameter method, a mathematical model of the working device’s center of gravity and its rotational inertia was established. Based on the characteristics of the excavator’s hydraulic system and the relationship between brake torque variations, a prediction model was developed to forecast the stopping position (brake rotary angle) of the excavator’s bucket after braking. Subsequently, the predicted results were validated using simulation and compared with existing experimental data to assess the accuracy of the model. The findings demonstrate that the predictive model exhibited high precision with minimal error. The utilization of this model enabled effective forecasting of the excavator’s braking position changes, providing a theoretical foundation for the intelligent remote control of excavators.