Water and soil loss prediction is an essential part of soil and water conservation program，and it is the scientific basis of soil and water erosion prevention and control.Water and soil loss prediction methods include slope erosion equation method， analogy method， classification and classification method， loss coefficient method， etc.According to the characteristics of Guangfeng branch and Yushan branch of Jiangxi natural gas pipe network project，using the classification calculation method calculate the amount of the new increased water and soil erosion of the project.The key areas and periods of water and soil loss control can be determined，and to provide guidance for the prevention and control of soil erosion.