Abstract: An algorithm based on the Euler-Lagrangian simulation framework is developed for analyzing the collection efficiency of a three-dimensional multi-body model. To predict the efficiency of droplet collection efficiently and accurately, the particle statistics method and the area ratio calculation method are integrated in the algorithm. A prior study for a standard model shows that the obtained results agree well with the experimental measurements under the normal droplet size condition. Based on the established algorithm, the droplet impingement characteristics on a high-lift configuration of a large commercial transport aircraft is simulated. The computational results show that the droplet trajectories converge and cross in the gap between the main wing and the slat and then the droplets hit on the trailing edge area of the slat. This phenomenon greatly enhances the local collection efficiency of the slat which is needed to be considered in the design of aircraft anti-icing system. Besides, the collection efficiency distribution on the lower surface of the main wing is different in the span direction, which demonstrates that the droplet impingement characteristics of the high-lift configuration are significantly influenced by the three-dimensional effect.