As an important part of the cryosphere, sea ice plays an important role in modulating the exchange of heat, fresh water and momentum at the air-sea interface at high latitudes, thus affecting the atmospheric and ocean circulation and even the global climate change. Under the background of global warming, Arctic sea ice has been declining since the satellite era, while Antarctic sea ice has shown a weak but positive trend until 2016, which attract the attention of scientists. The research shows that the change of Antarctic sea ice has three obvious characteristics: strong seasonal change, obvious regional difference and drastic interannual change. The strong seasonal changes and regional differences can be seen from the trend of sea ice concentration during 1979-2015: the trend of Antarctic sea ice is obviously stronger in austral summer and autumn than in winter and spring, and the spatial modes of sea ice trends in summer and autumn are similar, all of which show the decline of sea ice in Amundsen- Bellingshausen Sea and the increase of sea ice in Weddell Sea and Ross Sea, while the spatial modes of sea ice trends in winter and spring are similar, all of which show the decline of sea ice in Weddell Sea and Amundsen-Bellingshausen Sea. Compared with the feedback effects of the ocean, the atmosphere can control the sea ice change through the thermodynamic effects such as cold or warm advection, and the dynamic effects such as wind-driven sea ice drift, which plays a more direct role.