In the AntiThunderstorm design of buildings，multiple lighting rods are often used to form a joint protection range. To know the protection range of the multiple lighting rods needs to divide the protection range into three unequaled parts, and solve the ternary quadratic equations, which is difficult and has low efficiency. The AutoCAD’s vector calculation and the coordinate transform function are used to analyze the protection range of triple unequaledheight lighting rods, which is much simpler than solving the ternary quadratic equations.