The establishment of the China-ASEAN Free Trade Area has prompted closer cooperation in aquatic products trade between China and Vietnam. Studying the aquatic trade situation and export trade growth dynamics of China and Vietnam can help clarify the aquatic trade relationship between China and Vietnam and promote the sustainable development of bilateral aquatic trade cooperation. This paper analyzes the trade growth dynamics of aquatic products exported from China and Vietnam from 2002 to 2020 using the ternary marginal method. The trade growth pattern of aquatic products exported from China to Vietnam is "both quantity and price growth," and the trade growth pattern of aquatic products exported from Vietnam to China is "quantity growth mainly, extensive growth supplemented." The two countries have apparent differences in the growth dynamics of aquatic products export trade. Moreover, there is a higher complementarity when exporting Vietnam's aquatic products to China than China's aquatic products to Vietnam. Based on these, analyze the factors affecting the growth dynamics of Vietnam's aquatic products export to China: Vietnam's economic development level negatively affects the price index and quantity index of Vietnam's aquatic products exported to China, and Vietnam's aquatic product output affects the price index. China's trade freedom positively affects the price index and negatively affects the quantity index. Finally, this paper put forward suggestions to promote the sustainable development of bilateral aquatic products trade between China and Vietnam to facilitate the formulation of relevant policies between the two countries.