Abstract: The deposition characteristics of turbidite sand bodies in the X gas field, 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, this study employs frequency decomposition RGB attribute fusion technology combined with the FCM clustering algorithm to achieve a fine characterization of turbidite sand bodies, leading to the following three findings: ① The turbidite sand bodies in the study area exhibit strong amplitude and high continuity in seismic reflection characteristics. The RGB fusion results of frequency-decomposed seismic attributes at 15 Hz, 35 Hz, and 55 Hz best respond to the spatial distribution of turbidite sand bodies, with the predicted sand body thickness closely matching the actual thickness encountered during drilling, showing a correlation coefficient (R²) of approximately 0.94. ② The FCM algorithm effectively clusters the selected seismic attributes, preliminarily dividing the turbidite sand bodies into three categories based on the planar features of five clustering groups. ③ In the muddy sedimentary background of the study area, six sedimentary units are developed: banded lateral accumulation bodies, annular lateral accumulation bodies, channel banks, channel-branch channels, proximal blob bodies, and distal blob bodies. annular and banded lateral accumulation bodies, as well as the distal blob bodies, are predicted to be favorable sand bodies.