The invention discloses a recursive filtering method for dynamic imaging and a corresponding medical imaging device. The recursive filtering method comprises the following steps: S1, a neighborhood gradient value is used as a feedback coefficient to be introduced in a recursive filter structure, a recursive filter is formed, and the neighborhood gradient value decides output of the recursive filter in a recursive filter parameter index form; S2, according to requirements on image definition, a filtering layer number t is determined; S3, the recursive filter is adopted to carry out recursive filtering operation on the image at the kth layer, a kth-layer recursive filtering image is obtained and the kth-layer recursive filtering image is used as a (k+1)th-layer input image; and S4, k is gradually increased from 0, as each integer value is added, the step S3 is repeated until a (t+1)th-layer recursive filtering image is obtained, a tth-layer gain coefficient is combined, and a tth-layer scale image is obtained. The method of the invention can meet real-time requirements of dynamic imaging and can effectively suppress image blurring caused by interframe continuous movement, and good noise reduction effects are achieved.