The large-scale seaweed cultivation industry is one of the most active sectors in global fisheries. Over the past two decades, its growth rate has been more than twice that of the overall fisheries industry, indicating significant growth potential. China dominates this industry, accounting for 59% of the world's total seaweed production, including Laminaria japonica, Undaria pinnatifida, Pyropia/Porphyra spp., Gracilaria spp., and Hizikia fusiformis, with the highest production volumes globally. The aquatic seed industry serves as the "core" of aquaculture and the source of the entire industry. Approximately 99% of large-scale seaweed production are from artificial cultivation, highlighting the contribution and importance of new seaweed varieties to the industry. However, there are currently only 24 approved new varieties of large-scale seaweed, representing about 17% of new aquatic species for marine cultivation, which is not proportionate to its production share. Therefore, the present paper introduces the characteristics of the large-scale seaweed industry, the progress in breeding technology over the past 60 years, and the breeding achievements. It also offers recommendations to address the current challenges of outdated breeding techniques in the large-scale seaweed industry, aiming to provide insights for future research in seaweed breeding.