It aims to optimize the total resistance and the pitch amplitude of the KCS sailing in waves by adding two kinds of appendage, a pair of anti-pitch-fins at the bow and a wave suppressor at the stern, to the KCS and changing their size.Firstly, numerical calculations are performed on KCS with just a pair of anti-pitch-fins, just a wave suppressor, and both kinds of the appendage separately to study the effect on the hull of the appendages. Secondly, 30 KCS ships with deformed appendages are obtained by changing the width of the anti-pitch-fins and the length of the wave suppressor. The calculation uses the in-house viscous flow solver naoe-FOAM-SJTU. Thirdly, a Kriging surrogate model is established and applied to a multi-objective genetic algorithm to obtain the Pareto front of the hull with optimal appendages. Three KCS ships with optimal appendages are selected from the Pareto front to do further analysis.In the process of the pitch, appendages will generate resorting moment to lessen the pitch amplitude of the hull, the draft of the bow and stern. So the pressure of the hull will decrease, and reduce the pressure resistance and finally reduce the total resistance.