The invention discloses a method for making a de-icing policy of a tower line system through orthogonal analysis. The method comprises the steps of 1, building a three-dimensional finite element model of the tower line system; 2, determining a multi-factor two-level orthogonal table, compiling a multi-factor two-level orthogonal test scheme, and defining mechanics failure indexes of towers; 3, according to the multi-factor two-level orthogonal test scheme, applying designed wind load and ice load to a hanging position of each wire insulator and a hanging position of each ground wire respectively by adopting a finite element method, simulating stress conditions of each tower under different loads, and obtaining a maximum axial stress ratio and a dangerous unit number of an angle steel unit of each tower; and 4, for each index, calculating an index average value of each factor and each level, and obtaining a most serious icing condition according to the index average value, thereby obtaining an optimal de-icing sequence. According to the method, the most serious icing condition can be assessed under the condition of giving parameters of icing, a wind speed, a span and the like, and the optimal de-icing sequence of the tower line system is given.