Abstract Marine economic resilience can reflect the stability and health of the marine economic system and plays an important role in guiding regional marine economic development. Starting from the formation mechanism of marine economic toughness, the article establishes a marine economic toughness evaluation index system, selects marine economic data from 11 coastal regions from 2012 to 2022 as the research object, adopts the CRITIC-entropy weight method to solve the index weights, and measures the marine economic toughness using the TOPSIS model We introduce the kernel density estimation to explore the spatio-temporal evolution trend of marine economic toughness, use the barrier diagnostic factor to study the barrier degree of marine economic toughness and combine it with the OLS regression to analyze the influencing factors of marine economic toughness. In 2012-2022, Guangdong’s marine economic toughness score was 0.377, which is 2.25 times higher than that of Guangxi. Furthermore, various regions’ marine economic toughness shows a yearly upward trend. The kernel density curve of marine economic toughness is broad peak—sharp peak—broad peak; the obstacle factor of marine economic toughness is mainly adaptive capacity and renewal capacity; its obstacle degree is 0.383 and 0.374, respectively; and the marine economic toughness of the sea area will increase by 0.238% when the level of marine scientific research is increased by 1%. Optimizing the policy system and embracing technological innovation are inevitable choices to enhance the marine economy’s resilience in coastal areas.