The invention discloses a novel gait cycle generating method. The method comprises the steps of detecting all original gait cycles from a gait sequence to be processed according to periodic variation of pace width; setting a value k smaller than the minimum value among the numbers of frames in the original gait cycles to serve as the number of frames contained in a final cycle, wherein k belongs to multiples of 4; extracting k frames from each original gait cycle at equal intervals to serve as the representative frames of the cycle; obtaining the average frame of the representative frames on the same positions of the original gait cycles; calculating the coefficient of association between each representative frame in each gait cycle and the corresponding average frame, and selecting the representative frame with the highest coefficient of association to serve as the optimal frame of the corresponding position; obtaining the final gait cycle by means of the optimal frames on all positions. According to the method, incomplete frames and repeated frames in the gait sequence are eliminated, a gait cycle is generated by means of frames high in image quality, and then more accurate gait features are obtained and gait detection effect is effectively improved.