The utility model relates to an encoding and decoding method which makes use of the image signal of a base layer and a device of the method, which can code the image signal and output the bit stream of a first layer in the way of scalable dynamic compensation time filtering, and at the same time, can code the image signal and output the bit stream of a second layer in other ways of the base layer of a specified image signal. When the MCTF method is used to code, aiming at the image blocks in a frame in frame sequence of the image signal, the utility model uses standard blocks in at least a frame to get difference of each image element in the image blocks in the set which comprises frames adjacent in a former period or a later period with the frame in the frame sequence of the image signal and auxiliary frames which are in the former period, in the later period and in the same period as the frame in the frame sequence of the second bit stream. The utility model has the advantages of improving code rate in the way of using the frames in the second layer to make the image in the frame of the first layer.