Abstract: A composite heat insulating lining includes an upper lining and a lower lining. The upper lining and the lower lining each include an inorganic fiber prefabricated layer, and the inorganic fiber prefabricated layer is configured to reduce the heat conductivity of the lining, thereby reducing heat loss. In addition, existing inorganic fiber materials are generally not resistant to high temperature. The composite heat insulating lining provided according to the present application is provided with a refractory coating on a surface of the inorganic fiber prefabricated layer to avoid direct heating of the inorganic fiber prefabricated layer, thereby avoiding high temperature damage to the inorganic fiber prefabricated layer, and improving the service life of the composite heat insulating lining. An ethylene cracking furnace is further provided according to the present application, which includes any one of the above composite heat insulating linings.