The invention relates to a method and a device for accurately quickly measuring power transmission and distribution project leads. The method includes steps that firstly, a prism-free total station receives commands input by users and enters an arch length measuring mode and an arch sag measuring mode; secondly, the prism-free total station acquires coordinates of two frame suspension points A and B of a soft suspension bus and directly processes span, height, height different angle and required lead length of the frame suspension points by the aid of input given sag value; thirdly, the prism-free total station acquires coordinates of the two frame suspension points A and B of the soft suspension bus, measures coordinates of a lowest sag point D of the soft bus by utilizing a central point method and processes the coordinates to obtain sag values. Compared with prior art, the method and the device for accurately quickly measuring power transmission and distribution project leads have the advantages of simplicity in operation, short observation time, high measuring accuracy and no risks and the like.