The invention relates to medical instrument and signal processing technologies. For providing a generalized side-lobe blanking method for a medical ultrasonic system for improving the resolution of the system, the invention adopts the technical solution that a generalized side-lobe blanking method for ultrasonic system images comprises the steps of acquiring all low-resolution images using delay focusing, smoothing all the low-resolution images to obtain a low-resolution matrix, then calculating a covariance matrix, distinguishing desired signals from noise interference signals in combination with a generalized side-lobe blanking structure, and adaptively calculating a weight matrix to replace traditional non-adaptive weights, so as to improve the resolution of ultrasonic images. The method is mainly applied to image processing.