The invention belongs to the technical field of image processing, and discloses a code rate control method based on an H.264 video compression standard. The code rate control method comprises the steps of obtaining a video sequence in need of performing compressed encoding, wherein the video sequence comprises Q frames of video images, and each frame of the video image includes P macro blocks; setting a quantizer parameter of each macro block in a first frame of the video image into a constant parameter value to obtain the first frame of the video image after the compressed encoding; according to a complexity of an i-1th frame of the video image after the compressed encoding and an actual encoded bit number of the i-1th frame of the video image after the compressed encoding, determining a quantizer parameter of a first macro block in an ith frame of the video image; obtaining a quantizer parameter of a jth macro block in the ith frame of the video image; and performing the compressed encoding on the jth macro block, and determining the complexity and the actual encoded bit number of the ith frame of the video image after the compressed encoding till the Q frames of the video images after the compressed encoding are obtained. The problems that the computation burden is too large, the macro block layer control is not performed, and the consumed time of complexity computation is long in a code rate control implementation process in prior art can be solved.