The problem of how to make the plane layout better and reduce the influence of long-period waves through numerical simulation in the early design stage of the wharf in long-period waves sea area is studied.This paper uses the WW3 ocean wave model，MIKE21SW module，and MIKE21BW module to conduct a more comprehensive simulation of long-period waves which is verified based on the measured data. The simulation steps can be used as a general operation procedures for long-period wave simulation. To better reveal the impact of long-period waves on the ship’s response，the integrated waves are separated into short wave elements（＜30 s）and longwave elements（≥30 s），and Hs＜0.3 m is used as the preliminary judgment standard. It is concluded that the port general layout needs to expand the shielding range to block the main wave direction of long-period waves，and at the same time minimize the size of the entrance door to reduce the long-period wave input energy and reduce the wave height in the port.