Abstract: In order to study the hydrodynamic performances and motion amplitude response characteristics of the mariculture ship composed of truss structure and several floating bodies with plate and frame structures, we calculated the hydrodynamic characteristics of the ship in frequency domain based on the three-dimensional potential flow theory and Morrison equation. Then we obtained and analyzed the hydrodynamic parameters and motion response of the mariculture ship. The results show that the additional mass and radiation damping of the mariculture ship are sensitive to the change of frequency, and the sensitivity is obviously different in the movement of the mariculture ship in different directions, and the additional mass and radiation damping of the rotational motion are larger than those of the plane motion, which are both closely related to the structural shape of the mariculture ship. Under the action of incident waves in every direction, the first-order wave force of the mariculture ship increase at first and then decrease with the increase of frequency, and the first-order wave force curve tends to be stable in the high frequency section under the action of incident waves in different directions. However, there is a big difference in the middle and low section. Under the action of high-frequency and low-frequency excitation, the motion response of the mariculture ship is small, but the resonance occurs when it moves in the medium and short period regular waves. The surging and pitching are the main motion modes when ship with follow wave or head wave condition, and roll and heave motions are the main motion modes in bean wave.