PURPOSE: A spray type flame retardant insulating composition is provided to be easily handled and constructed, to have excellent heat-shielding, flame-shielding, and fireproofing functions without generating harmful gas. CONSTITUTION: A spray type flame retardant insulating composition includes 50-70 wt% of an inorganic binder, 5-10 wt% of a silica aerogel, 4-7 wt% of an inorganic fiber, 20-30 wt% of an inorganic hollow body, and 1-3 wt% of a silane compound. A manufacturing method of the flame retardant insulating composition includes a step of manufacturing an inorganic binder; a step of mixing a silica aerogel into the inorganic binder; a step of mixing an inorganic fiber into the mixture; a step of mixing a porous inorganic hollow material into the mixture; and a step of mixing a silane compound into the mixture.