Large aquaculture engineering vessels are mainly operating in the deep sea. In order to ensure the sufficient strength of the hull structure under various working conditions and fish farming arrangement, it is necessary to design the structure of the aquaculture engineering vessels. For the reasons that the type and service condition of aquaculture engineering vessel are special, there is no current specification written specifically for its particularity. According to the characteristics of its overall layout and loading, the basic size and specification of the hull structure are calculated in accordance with the applicable section of the code for double-hull tankers, and the finite element model is established according to the actual loading condition to calculate the structural strength by the finite element method. The results of calculation and analysis show that the structure size and specification calculated by the code for double-hull tankers basically meet the requirements. If the strength of the local structure is not up to the strength requirements, the strength requirements can be met after the strengthening of the structure. By carrying out the basic design of hull structure with similar vessel in the code and checking the structural strength with the finite element method, it is proved that the calculation method meets the requirements of structural design.