The invention provides an oblique stacking peak amplitude portion edge detecting method for event automatic picking. The method comprises the steps that 1. pre-stacking CSP data are used for wavelet transforming, and a signal analysis part is obtained; 2. according to the analysis part obtained in the step 1, signal instant amplitude is obtained; 3. local linear Radon conversion is carried out on a profile of the instant amplitude, the peak amplitude of instant amplitude is picked, and an oblique stacking peak amplitude profile is obtained; and 4. based on the oblique stacking peak amplitude profile, an edge detection profile is obtained, and event and travel time picking is carried out on the edge detection profile. Oblique stacking conversion is carried out on an instant amplitude profile, the instant amplitude profile is smooth compared with original seismic recording, a plurality of low-frequency components are contained, a part of high-frequency glitch noise can be filtered away, and the event positions of the two parts are the same. Noise is effectively suppressed, the problem that continuous events cannot be picked in a large offset distance easily through an existing method is overcome, operation is convenient, and event automatic picking is achieved.