Abstract: Deep Ordovician carbonate reservoir is the main exploration target in Tazhong area.The undulate dunes,the loose surface sand bed and the serious absorption & attenuation effect leads to low SNR seismic data of the target layers.The noise caused by sand dunes affects the characteristics of the effective wave,and also breaks the law of the coherent noise,which increases the difficulty for seismic data denoising processing.In order to suppress interference wave and improve the SNR of Ordovician target layers with the premise of fidelity,based on the experience and recognition obtained from the desert seismic data processing in the last few years,in terms of noise type,energy strength,frequency bandwidth and their characteristics in different domain,we proposed multi-domain composite denoising technique and processing workflow,and the multi-domain includes scale,step,frequency,domain,time window,zone etc.Actual data application results indicate that mlti-domain composite denoising technique obviously improve the SNR of Ordovician insider reflections,the clearness of small fault points,inside abnormal of carbonate or moniliform reflection.