To respond to the global climate change and to help achieve the “double carbon” goal in China, this paper proposed an idea of implementing the “Blue Carbon Project”offshore moored kelp farms. Based on this idea, the design and analysis procedures for the offshore moored kelp farms were described, and numerical simulations of core breeding facility in the kelp farm module were also conducted. The results show that tension values of mooring ropes, breeding boom ropes, connecting ropes and lifting ropes do not exceed the breaking limit values in extreme sea conditions. Besides, the heaving motion of buoys makes little impact on the regular sunlight exposure of seaweed and the breakage of seaweed’s holdfast is an event of low probability. The design and analysis method proposed in this paper will provide a reference for the mooring design of kelp farms with a water depth over 40 m.