The calculation of water droplet impact characteristics is essential for predicting aircraft icing. The Lagrangian method is commonly used because it can track particle trajectories, deformation, breakup, and splashing. However, its 3D computational speed has been criticized. This paper proposes a parallel strategy based on particle parallelism, which enhances the computational efficiency of the Lagrangian method. The method partitions the domain by particles to calculate the water drop field, as shown in Figure 1, maximizing parallelism efficiency. This approach's effectiveness has been demonstrated on two-dimensional NACA23012 airfoils, with a remarkable acceleration effect. As shown in Figure 2, the time required for the case is reduced to one-fourth of the time required for a single core with an increase in cores. It is expected that extending this method to 3D and achieving parallelism on a larger scale will further reduce 3D Lagrangian computation times.