Aquaculture equipment is moving from offshore areas to the deep sea to obtain a cleaner farming environment, but will suffer from a worse marine environment. Truss-type aquaculture floating platforms have gradually gained the favor of deep-sea and ocean aquaculture due to being resistant to corrosion, lightweight, easy to move, having modular assembly characteristics, and so on. Here, a modular aquaculture floating platform that is mainly composed of high-density polyethylene non-metallic pipes as a floating body, a truss structure support and a single-point mooring system is designed. The three-dimensional potential flow theory and Morison equation are applied to the motion and force prediction of discontinuous and open structures, and an evaluation method for analyzing the hydrodynamic performance of the platform system is proposed. Then, a sensitivity analysis of the dynamic response is conducted on the density and length of the bottom floating pipe arrangement of the truss-type aquaculture floating platform. The results show that the pitch motion of the heading direction and the roll motion of the beam direction have a remarkable effect on the hydrodynamics of the truss-type aquaculture floating platform, and the maximum amplitude is 12.9 deg and 10.8 deg, respectively. The effective tension under the heading direction is greater than that under the Beam direction. And the sparser the arrangement of the floating pipe is and the longer the length of the floating pipe is, the more improved the hydrodynamic performance of the floating platform will be, but the effective tension is greatly affected by the wavelength and period, so it is necessary to design the appropriate floating pipe length according to the actual marine environment. This study could provide an engineering reference for the design, analysis, and application of an aquaculture floating platform.