Disclosed is an object motion trajectory photographing method. When an object motion trajectory photographing instruction is detected by a terminal, same photographs one picture at every preset exposure time; the terminal determines whether or not a preset flag is provided in a preset storage path; upon determination that the flag is provided in the preset storage path, the terminal composites the photographed pictures with object motion trajectory pictures coming before the flag to produce an object motion trajectory video. Also disclosed are an object motion trajectory photographing system and a computer storage medium.