Abstract: Aiming at the actual situation that the amplitude may be distorted in a mixed sedimentation environment, by using the example of Carboniferous Ⅳ sand group in the south of Sangtamu area, based on the analysis of the single well sedimentary facies, we select the useful amplitude information in sandstone to perform AVF frequency-divided inversion, combine the results with attributes, establish coupling relationship between the amplitude attribute and the sand body, establish the sand body recognition mode, and characterize the plane distribution of the sedimentary facies. The seismic reflection structure type is subdivided into four types. Based on the top surface of the Ⅳ sand group, the average crest amplitude attribute extraction was carried out 10 ms above and below, AVF frequency-divided inversion was carried out in the southwest with heavy gray matter content. There is a positive correlation between the amplitude attribute and the sand body, and the higher the sand content, the larger the amplitude. Underwater distributary channel are mainly distributed in the S1072 well area and the northwest margin of the study area. Sand flat are mainly distributed in the AT10 and S111 well areas, exhibiting a sheet. Tidal sand ridge are mainly distributed in the south, and can be used as a research area to find the key areas of lithologic traps.