The invention relates to a method and a system for real-time monitoring of an analog wire coated by ice of an overhead power transmission line. The method comprises the following steps of: (1) mounting a section of analog wire having same model and material with the line lead wire on a tower of the overhead power transmission line; (2) arranging a measuring head on the analog wire for measuring weight of the analog wire; (3) ordering that coating ice of various types and with different section shapes is converted to a circular glaze section with density of 0.9g/cm<3>, wherein calculation formula of ice coating thickness b of the analog wire in a unit length is FORMULA, wherein D (mm) is the outer diameter of the analog wire; a known parameter w1 is self-weight load of the analog wire; anda known parameter w3 is vertical total load when the wire is coated by ice and can be measured by the measuring head. The invention has the advantages of reasonable and correct measurement of synthetical load of the line coated by ice and thickness of the coating ice, simple algorithm and accurate result.