As an important parameter of the Earth's ecosystem, ocean temperature has always been a hot research field for scholars, and the rise in ocean temperature caused by global warming is a topic related to the fate of humanity. The prediction of future ocean temperature is of great significance. The ARIMA model, as a typical prediction model, is highly favored by scholars from various countries due to its accuracy and adaptability. In this paper, the ARIMA multiplication model with seasonal effect is used to forecast the trend of ocean temperature change in the next year, and to prediction graph as well as specific reference values are given. The conclusion is as follows: The global average monthly ocean temperature will continue to rise in the next year. Therefore, this article believes that the government should promptly introduce relevant policies to address the rise in ocean temperature caused by global warming, and people should also fulfill their obligations to protect the environment.