Abstract: The deposition characteristics of turbidite sand bodies in the X gas field in the Yinggehai Basin, South Chin Sea, controlled by shallow marine turbidity current sedimentary systems, are complex and spatially distributed unclearly, which restricts the development of oil and gas resources. Based on well logging, core, and 3D seismic data, we combined frequency decomposition RGB attribute fusion technology with the FCM clustering algorithm and achieved a fine characterization of turbidite sand bodies. Results show that ① The turbidite sand bodies have strong amplitude and high continuity in seismic reflection. The RGB fusion of frequency-decomposed seismic attributes at 15, 35, and 55 Hz best responded to the spatial distribution of turbidite sand bodies, and the predicted sand body thickness well matched the actual thickness seen in drill hole, showing a high correlation coefficient (R²=0.94). ② The FCM algorithm effectively clustered the selected seismic attributes, and divided the turbidite sand bodies into three main categories based on the planar features of five clustering groups. ③ In the muddy sedimentary background, six sedimentary units could be recognized, i.e., banded lateral accumulation bodies, annular lateral accumulation bodies, channel banks, channel-branch channels, proximal lobe bodies, and distal lobe bodies. The annular and banded lateral accumulation bodies, as well as the distal lobe bodies, are good targets for sand mining.