The invention provides an image feature extraction system and method based on Talbot effect optical convolution. An optical convolution image processing system is composed of an optical system, a laminated grating, a time-sharing switching system and a detector. The optical system comprises an objective lens, an ocular lens system and a source image and is used for realizing conjugate reduction imaging of an object image. The laminated grating system can generate a Talbot self-imaging effect on a grating Talbot distance, and then optical convolution processing can be carried out on an incidentlight field by utilizing a Moire fringe effect. The time-sharing switching system can realize time-sharing switching of gratings with different periods and different phases, thereby realizing opticalconvolution operation with different convolution parameters and extracting different incident image features. According to the method, image processing is carried out by using optical convolution, sothat the calculation energy consumption can be obviously reduced and the calculation time is saved. According to the scheme, the structure system is compact, and operations such as image filtering can be performed by effectively utilizing optical convolution.