Abstract Sea ice monitoring is one of the important guarantees for marine operation and transport. The space borne remote sensing techniques have the advantages of wide area surveillance, multi-temporal resolution, prompt acquisition, and high precision. They have become one of the key sea ice monitoring techniques. The new Chinese satellite HJ-1A/B CCD images were used in the sea ice monitoring of the Nanpu sea area in winter, during the time from Nov. 29, 2008 to Feb. 21, 2009. A fast processing work flow was established based on the object-oriented information extraction technology. It was used to map the change of the ice area during the period. According to the ice area change, the ice sea distribution, and the historical meteorological information, the ice period was divided into: initial ice (early Dec., 2008 to the end of Dec., 2008), abounding ice (from the end of Dec., 2008 to the end of Jan., 2009), ice thawing (from the end of Jan., 2009 to the end of Feb., 2009). The work contributes to the safe construction of the artificial islands in the Nanpu-4 structure during the icebound season. The study shows that the remote sensing technology is a practical and effective technical means for the sea ice security monitoring of oil fields' exploration, development and engineering construction in beaches.