Abstract: This study used the ERA5 reanalysis data provided by ECMWF to analyzed the spatial distribution, seasonal characteristics and long-term variation trend of energy flow density in the Gulf of Guinea in 1979-2020. The result showed that: ① The wave energy gradually decreases from sea to land, and the wave energy of southwest part of the study area is higher than that of the northeast part of the area. The spatial distribution of wave energy in each season is quite different: the wave energy in summer mainly shows a north-south distribution difference, while the wave energy in winter mainly shows an east-west distribution difference. And, the wave energy in summer is higher than that in winter. As the transitional season, wave energy in spring and autumn lies between those in spring and winter. ② The wave energy in most areas of Gulf of Guinea shows an apparent increasing trend. The growth rate is largest in the southeast part 0.06 kW·m⁻¹·a⁻¹, and gradually decreases from southeast to northwest. ③ In terms of regional average, the wave energy of Gulf of Guinea is increasing 0.025 kW·m⁻¹·a⁻¹ because of the wave energy growth in summer. The change trend of wave energy varies in different seasons: the proportion of wave energy in autumn and winter is smaller with almost no variations, relative to that in spring and summer. This part of wave energy in spring transfers to summer with a rate 0.05% per year.