In this study, a seabed comprising numerous particles was simulated using discrete element method. To express the viscosity of the seabed, the material and cohesion properties of medium clay were used. The trawl door was defined by a series of polygons. Researchers used the CATIA software suite to obtain polygon data for the trawl door: First, the shape model of the trawl door was established. Next, mesh data were exported to a text file used to define the polygon elements in the program. To reduce analysis time, parallel computing (general-purpose computing on graphics processing units) was used. Following the L9-Taguchi experimental design method, the design parameters of the trawl door were determined using three levels of four factors including the front fillet angle, length and depth of the trawl door; and angle of attack. The average trawl door contact forces were compared to determine optimal trawl door design.