Abstract: A three-dimensional numerical model of the dam is established based on the CFD software Fluent to investigate the feasibility and effectiveness of applying the assembled quick closure devices to address the dyke breach issue in flood season. After verifying the reliability of the numerical method by use of relevant model test data, the horizontal current force and overturning moment acting on the dam under different working conditions are obtained. The pertinent results indicate that the horizontal current force goes up with the increase of the flow velocity, and the width and depth of the breach. The added rows of the fabricated rapid closure devices would make the current force slightly enlarge. In addition, the larger the flow velocity is, the more obvious the effect is. The overturning moment caused by the flow force, however, has little effect on the stability of the dam.