The invention discloses an analysis method for the continuous collapse of a power transmission tower-line system which is characterized by comprising the following steps: analyzing to obtain static internal force of to-be-dismantled component, a natural vibration period and a natural vibration frequency of the power transmission tower-line system after to-be-dismantled component is dismantled in apower transmission tower-line system finite element model; calculating the breaking time of each power transmission line, and compiling a command flow; Killing the to-be-dismantled component to generate a dead unit, and applying equivalent static internal force to a joint where the to-be-dismantled component is connected with the rest structure; And performing transient dynamic analysis on the residual structure. According to the method, the rod piece which can cause continuous collapse of the power transmission tower after being damaged can be analyzed, the design requirement of the rod piece needs to be properly improved during engineering design, and a reference is provided for design of the power transmission tower.