The present invention relates to the technical field of printing in particular, to a frequency multiplication method and device, for solving the problem of poor quality of a printed image. One method comprises: for two adjacent pulse signals output from an encoder, determining a first kind of pulse signals and a second kind of pulse signals to be inserted between the two adjacent pulse signals according to a time interval between the two adjacent pulse signals and a frequency multiplication value corresponding to a longitudinal resolution; determining a period of the first kind of pulse signals to be inserted between the two adjacent pulse signals, and determining a period of the second kind of pulse signals to be inserted between the two adjacent pulse signals; and performing frequency multiplication processing on the two adjacent pulse signals. The embodiments of the invention further improve the printing quality of images.