The invention provides an analysis method of a transmission line wind-ice coupling load line breakage effect. The analysis method includes the following steps that 1, geometric parameters and physical parameters of a transmission tower line system are determined, and a transmission tower line system analysis model is established; 2, icing loads of the transmission tower line system are determined; 3, a non-linear analysis method of a transmission tower line system reaction under the effect of the icing loads is established; 4, a wind load model in which the wire icing thickness changes is established; 5, a dynamic analysis method that a transmission wire is broken under the effect of wind-ice coupling loads is established, and the dynamic effect of transmission line icing line breakage is analyzed and calculated. According to the method, the coupling effect of the icing loads and wind loads is considered at the same time, the analysis formula is displayed and expressed, the calculation speed is high, the calculation amount is small, and the defects of existing traditional methods can be effectively overcome. The method is suitable for analysis and calculation of the icing line breakage effect of various transmission tower line systems with different spans and sags under the effect of the ice-wind coupling loads.