Excessively short distance between high voltage transmission lines will lead to serious faults such as flashover and short circuit. In order to prevent the danger caused by such faults

we put forward a measurement method of space across transmission lines based on binocular ranging. The method is based on the improved chain code algorithm

and the automatic detection algorithm of transmission line is designed to extract the pixel coordinates of transmission line; according to the binocular ranging principle

a geometric measurement model of the space crossed transmission line was built to calculate the transmission line spacing. Finally

the method was applied to the on-site measurement of 2 transmission lines in Shanxi Yangquan. The actual measurement results show that the method can effectively detect

fit and combine the lines to be measured. In the geometric measurement model

the transmission line spacing can be accurately measured both in parallel or space crossing transmission line

then automatic detection and non-contact measurement can be realized by this method. Compared with the measurement results of the electronic total station

the maximum measurement error of the new method is less than 2%

which verifies the method is accurate and effective

and meets the requirements of actual measurement.