To solve problems of existing devices for sorting foreign materials from laver (Porphyra tenera), such as the low working efficiency and clogging proneness, a non-clogging equipment for sorting foreign materials was designed. In the equipment, the filter suction device was composed of several parts including a combined filtering cartridge, anti-clogging foreign-material removal device, and so on. Based on the Lagrange’s equation, dynamic modeling and simulation of suction device were carried out to analyze the effects of slit width and cylinder rotation speed on suction efficiency under multiple working conditions. Results show that the device exhibits the highest efficiency of suction filtration when the width of filtering slots and rotational speed of the filtering cartridge are 0.6 mm and 200°/s(33 r/min). Based on the simulation results, the range of the three experimental factors was determined, and the removal rates and filtration time were used as the response indexes. The three-factor and three-level experiments were designed by Minitab software, and the three-dimensional model of the response surface was established. The optimization results show that when the width of filtering slots is 0.6 mm, rotational speed of the filtering cartridge is 33 r/min, and flow rate at the discharge is 16 m³/h, the removal rate is 98.44%, and the filtration time is 2.72 min. The results provide reference for the design and optimization of equipment for sorting foreign materials from laver.