Seamounts constitute some of the most direct evidence about intraplate volcanism, and can profoundly affect physical and biological processes, mesoscale circulation and primary production. Caiwei Guyot locates within the Magellan Seamounts of the Northwest Pacific Ocean, where is one of the key investigation areas discovered, named and responsible for resource exploration by China. In this study, we carried out detailed rock magnetic investigations on a sedimentary sequence obtained from the Caiwei Guyot. The methods include hysteresis loops, isothermal remanent acquisition curves, and first-order reversal curves. It is found that the magnetic minerals in the surface sediments of the Caiwei Guyot are mainly fine-grained magnetite with low coercivity; and three magnetic sub-groups with different coercivity values can be mathematically distinguished by a log-normal distribution function, inferring that the change of the coercivity of the magnetic particles can effectively indicate the intensity of the early diagenesis of the sediments. Referring to the physical ocean process, we speculate that the production changes of the Antarctic bottom water and solar insolation may affect the environmental evolution of ocean bottom. Therefore, we suggest that this result provides new perspective to explore the possible impacts of the Antarctic climate on the North Pacific, and to assess the interactions between the upper and lower parts of the oceans, which both may have directly contributed to global changes.