The wet filter dust collector (WFDC) is widely used in dust control in various industries, but its dust collection mechanism is unclear, and the influence of the metal-based filter screen (MBFS) inclination angle on the dust removal performance is still uncertain. In this paper, the liquid film crushing and collecting dust mechanism of MBFS and the influence of its inclination angle on the dust removal performance of WFDC are studied. The results show that with the increase of inclination angle (30° to 150°), the average pressure drop of WFDC first decreases and then increases, the average dust concentration first increases and then decreases, and the MBFS dust removal performance is optimal at 90°. The optimized WFDC was applied on-site in a coal preparation plant, which exceeded the dust suppression efficiencies of 91 % and 88 % for total dust and respirable dust, respectively. The research results are expected to provide theoretical guidance for WFDC design and improvement.