The invention relates to a frangibility prediction method for the large power grid. The method is characterized by comprising the following steps that 1) power-grid rack program data and a system operation constrained condition are obtained; 2) a complex network mathematical model of the power grid is established according to the obtained constrained condition; 3) aimed at the complex network mathematical model, the purely graph-theory betweenness, the line capacity based trend distribution factor electric betweenness and the transmission capacity based trend distribution factor electric betweenness of each node/side are calculated; 4) a static fragile link of the grid is determined according to the three types of betweennesses obtained in the step 3); 5) a dynamic fragile link of the grid is determined by taking the three types of betweennesses in the step 3) as the basis; and 6) the static fragile link is integrated with the dynamic fragile link to obtain a fragile link of the whole large power grid. According to the invention, the large power grid is analyzed conveniently and effectively by utilizing complex network theories, so that a design staff can carry repeated examination and timely adjustment in the design process of the rack structure, and the process is simple.