Abstract: In video investigatio, gait inspection mainly relies on individual observation ability and experience, which is subjective and leads to differences in the judgment of gait characteristics of the same individual. Therefore, it is necessary to propose the conception of a video based gait inspection method to assist in reconnaissance. Literature analysis, comparative analysis, and investigation and research methods are utilized, 2D joint points are extracted from video frame sequences, and 3D pose sequences are mapped. Then, gait feature parameters obtained from 3D motion capture equipment are referenced to achieve accurate measurement of gait feature parameters in video images. Finally,likelihood ratio method is used to evaluate gait inspection features. The method has been demonstrated by experts and has strong theoretical innovation value. It proposes a development direction for gait investigation in the future, providing a research basis for improving investigation efficiency and the evidential value of gait in forensic science.