The invention discloses a method for self-adaptation ultrasonic imaging of a spatio-temporally smoothed coherence factor type. The method comprises the following steps that (1) beam forming preprocessing is conducted; (2) beam forming processing is conducted, wherein beam forming processing comprises the steps that delayed focusing is conducted on each channel received signal, a coherence factor value of the spatio-temporally smoothed coherence factor type is calculated according to the channel received signal after delayed processing, and weighted processing is conducted on the coherence sum of the received signals through coherence factors so that beams of each scanning line can be obtained and output; (3) beam forming post-processing is conducted, wherein beam forming post-processing comprises the steps that envelope detection, logarithm compression, scanning conversion and display are conducted on the scanning lines. According to the method for self-adaptation ultrasonic imaging of the spatio-temporally smoothed coherence factor type, side lobe can be restrained, sound disorder is reduced, the contrast ratio of an image is improved, an artifact is remarkably eliminated, the imaging quality is improved, the calculation complexity is low, and the method is easy to achieve in hardware.