The invention discloses a method and device for measuring an icing thickness of a power transmission line. The method comprises the steps of collecting a four-eye image of the power transmission line;inputting the four-eye image of the power transmission line into a convolutional neural network model, and outputting a target parallax error point set of the power transmission line; calculating a depth point set of the power transmission line according to the target parallax error point set of the power transmission line; determining a three-dimensional model of the power transmission line according to the depth point set of the power transmission line; obtaining cross section information of a conducting wire of the power transmission line according to the three-dimensional model of the power transmission line; and determining an equivalent icing thickness of the power transmission line according to the cross section information of the conducting wire of the power transmission line. Byadopting the method for measuring the icing thickness of the power transmission line in the scheme, visual matching is performed on the four-eye image of the power transmission line based on the convolutional neural network model, the accuracy of measuring the equivalent icing thickness of the power transmission line is improved, and power companies can be effectively guided to perform deicing work.