With high spatial resolution of 250 m, MERSI images obtained from FY-3 satellite not only reveals information about the long term distribution of sea ice in large scale, but also contains information about its detailed shape characteristics, such as ice block area and roundness. Based on the spectral feature of sea ice and gray distribution feature of ice block, an integral method and process for extracting the macroscopic sea ice distribution and detail ice block shape parameters was proposed in this paper. This method consisted of sea ice recognition, ice block detection and sea ice parameters extraction. In the summer of 2014, the detail sea ice information of the marginal ice zone in the Fram Strait was extracted accurately by using the proposed method. And consequently this method can provide methodological support and information security for the study on the change of Arctic sea ice and interaction between atmosphere and ocean.