Proportion marking scale for digital photo and marking method thereof

The invention relates to the field of engineering surveying, and particularly to a proportion marking scale for a digital photo and a marking method thereof. The marking method is characterized by projecting light spots on a surface of a measured object while photographing digitally by utilizing the non-divergence characteristic of laser, so that the practical size of the measured object and mutual distances between the measured object and surrounding high-voltage devices can be calculated from the photo, wherein the specific operating steps are as follows: 1) projecting laser emitted by a laser source of the proportion marking scale to a measured object to form multiple light spots; 2) measuring the practical size of the photographed object based on the size of the light spots in the photo, and calculating out the mutual distances between the measured object and the surrounding high-voltage devices. The beneficial effects of the invention are that: the proportion marking scale has the advantages of being sim