The dynamic changes in line length of high-voltage transmission lines under different loads can affect the results of traveling wave distance measurement based on fixed line length. This paper assumes that overhead ground wires are not affected by loads. Using ground wires as a reference

image recognition positioning technology is applied to calibrate the relative coordinates of ground wires and transmission lines. Based on the theoretical derivation of overhead line equations

dynamic correction of transmission line length is achieved. Considering the scenarios of equal and unequal heights of transmission towers

based on the catenary equation

the ratio of stress to specific load is transformed into a single variable

and a transmission line length correction model is constructed corresponding to the ground wire transmission line height difference H identified and located by image recognition. It further considers the visual distribution of equidistant multi-point height differences

applies curve fitting technology

and achieves dynamic correction of transmission line length. Finally

the corrected line length is applied to single end and dual end traveling wave ranging

and a comprehensive traveling wave ranging weight allocation based on minimum error is proposed. The simulation verifies the effectiveness of line length correction and ranging accuracy proposed.