Abstract: The information of different angles is necessary in the extraction of prestack attributes and prestack inversion.The suppression of surface wave,random noise and coherent noise in actual data will impact the quality of angle gather data more or less.Since actual data is complex,it is difficult to quantitatively evaluate the influence of prestack denoising on angle gather data.Aiming at the problem,a theoretical model was built to carry out quantitative research.The results indicates that ① the anti-noise ability of angle domain stacking is much better than that of CMP stacking,moreover,for angle domain stacking,the minimum signal to noise ratio can be up to 0.5;②The effect of coherent noise on angle gather is smaller than that on CMP gather and coherent noise only affects local traces,and the influence will be larger if the apparent velocity of coherent noise is large;③surface wave has strong energy and low frequency and a small amount of residue will affect the angle gather obviously.As surface wave mainly occurs in near offset,which has more influence on near traces.