An object dimension measurement method and apparatus, where the object dimension measurement method includes obtaining a horizontal distance between a photographing terminal and a photographed object or a vertical distance between the photographing terminal and a horizontal plane, obtaining a camera imaging angle when the photographing terminal photographs the photographed object, calculating a deflection angle of a camera in a vertical direction when the photographing terminal photographs the photographed object, obtaining through calculation an imaging distance of the photographed object on a display screen of the photographing terminal according to a trigonometric relationship among the horizontal distance or the vertical distance, the camera imaging angle, the deflection angle, and the imaging distance, and obtaining through conversion an actual dimension of the photographed object according to the imaging distance. Hence, an object dimension can be accurately measured without using a special measuring tool.