Data recored by Acoustic Doppler Velocimeter(ADV) are usually affected by several foctors,including singal asliasing and Doppler noise,etc,which causes there are many spikes occuring in the data demanding us to despike it. This paper includes two steps to despike ADV data which was measured in the Three Gorges and the the whole process includes the first one is using the modified versionof phase-space thresholding(PST) method which proposed by Parsheh to detect the spike and extrapolation is applied in the second step.