To facilitate the rational development of engine-propeller integrated control curves and improve the loading response and rapid starting of vessels equipped with a Combined Diesel And Diesel (CODAD) system, mathematical models for the diesel engine, gearbox, shafting, and propeller were established. By analyzing shortcomings of the original emergency loading strategy, an optimized strategy was proposed that prioritizes increasing the rotational speed before adjusting the rate of pitch change. Dynamic simulation results of the CODAD system demonstrate that the optimized strategy ensures that the engine power remains within the overload limit while significantly accelerates the response to engine commands and vessel starting. Compared with three representative strategies, the speed stabilization time under optimized strategy is reduced by 76.6 s, 37.6 s, and 23.8 s, respectively, and the command loading time is shortened by 78.3 s, 35.4 s, and 24.7 s, correspondingly. The simulations also reveal the power variation pattern during emergency loading of large vessels: the main engine power initially increases, then decreases, and finally stabilizes as the vessel's speed steadies. This study provides valuable insights for formulating overload protection strategies and optimizing engine-propeller matching design.