The present invention provides a step counting method and device. The method comprises the following steps performed repeatedly: a) obtaining three monoaxial acceleration signals with a predetermined length from triaxial output of a triaxial acceleration sensor worn on a walkrunner; b) performing high-pass filtering on each obtained monoaxial acceleration signal; c) performing pitch detection on each high-pass filtered monoaxial acceleration signal; d) using the pitch obtained in each pitch detection as a cut-off frequency to set a low-pass or band-pass filter, and performing low-pass or band-pass filtering on corresponding high-pass filtered monoaxial acceleration signal by using it; e) obtaining acceleration signal extreme value points from each low-pass or band-pass filtered monoaxial acceleration signal and removing interfering extreme value points therein; f) counting the number of the acceleration signal extreme value points after the interfering extreme value points have been removed; g) determining the accumulative walkrun step number of the walkrunner. The method can count steps accurately.