The invention relates to a foaming flame-retardant coating for a curtain. The coating comprises matrix emulsion composed of ethylene-vinyl acetate copolymerized resin, 3(2, 3-dibromopropyl) isocyanurate, association type waterborne polyurethane emulsion, polyacrylate emulsion, fumed silica, sulfo succinate, sulfo succinamide, a silicon-nitrogen compound, oxirane/epoxypropane segmented copolymer, modifier, wood fiber powder and aluminic acid ester. By means of the finishing process of the foaming flame-retardant coating for the curtain, the requirement for the finishing process of a heavy fabric can be met, physical foaming is directly conducted on the coating through a mechanical foaming machine, and then coating finishing is conducted, and meanwhile the defects that an original curtain fabric is poor in moisture absorption performance, carries static electricity easily, is poor in air permeability and the like are overcome.