Challenges in current research on fine mesh wet screening (≥50 mesh) include representing fine wire boundaries, contentious porous media handling, and low computational efficiency. To address these challenges, this study employs an averaged SPH-DEM method for modeling solid-liquid flow on screen. It integrates the Symplectic scheme and quaternion method to enhance computational accuracy and scalability. The fine wire boundaries are discretized into spheres to facilitate hertz contact of DEM particles, and a novel screen aperture-fluid resistance model is introduced to calculate the resistance exerted on SPH particles by screen surface. The simulation results of dam break and periodic screening exhibit robust consistency with experimental data and other models, effectively validating the feasibility and accuracy of this methodology. Moreover, simulations of continuous screening using a 0.2 mm wire demonstrate that liquid enhances particle passage, further substantiating the practical viability of employing this model for simulating fine mesh wet screening.