An umbrella type structure of composite insulator used in high-altitude ice-coated area is composed of at least two umbrella skirts as large, middle and small diameters. The invention is characterized in that the distance between umbrella skirts is 35-40mm, the distance between large umbrella skirts is 170-220mm, the diameter of large umbrella skirt is 170-220mm, the diameter ratio between large and small umbrella skirts is 1.8-2.1, the diameter ratio between large and small umbrella skirts is 1.3-1.5, the pitch angles of upper surfaces of large, middle and small umbrella skirts are 8-9 degrees, the pitch angles of lower surfaces of large, middle and small umbrella skirts are 0 degrees. The invention can be used for the external insulation engagement of power transmission system more than 110KV at high-altitude ice-coated area. The invention has reasonable structure, high ice flash voltage, low local field strength, and wide application, which can resist ice slush bridge umbrella skirt.