Abstract: Based on the Michell integral method of the thin ship linear wave resistance theory，the linear superposition principle of the Cochin function，and the curve fitting with orthogonal Chebyshev polynomial，this paper derives the general numerical formula for the linear wave resistance of monohulls，trimarans and pentamarans. Bases on the formula，the wave resistance of Wigley pentamaran samples under different outrigger arrangement configurations is calculated，and the influences of the outrigger arrangement on the wave resistance is analyzed. Moreover，by employing the genetic algorithm together with the derived formula，an optimization on the outrigger arrangement design is carried out to reduce the wave resistance at required traveling speeds. Simulation results show that both the wave resistance formula and the corresponding optimization scheme are effective and feasible in engineering applications.