Abstract: The Landsat series satellites are the remote sensing resource series satellites, which are jointly managed by National Aeronautics and Space Administration and United States Geological Survey. Large quantities of high-resolution and stable image data provided by the Landsat series satellites have created good opportunities for the earth remote sensing exploration activities in the past forty years. Satellite remote sensing data preprocessing is the first step for obtaining remote sensing image, and has an important impact on the quality of the satellite remote sensing product. Aimed at tackling the Landsat8 raw data, the authors dealt in detail with the space data transmission protocol and data transmission format for Landsat8 data downlink. The preprocessing steps for raw data were analyzed, which included synchronization, transfer frame analyzing, unpack, mission data extracting, etc. In addition, the procedure of 0 - level image product acquisition was described. Specifically, based on CCSDS ( consultative committee for space data systems) recommended standard, the authors also discussed the method and technological process of lossless data decompression for Operational Land Imager ( OLI ) compressed data. The Landsat8 Level 0 data product obtained by the data preprocessing can provide high-quality basic images for the application of Landsat8 satellite remote sensing data.