The invention discloses an energy-saving environment-friendly flame-retardant architectural paint which comprises the following components in parts by weight: 30-50 parts of cement, 20-50 parts of paste ash, 10-25 parts of coal slag powder, 10-35 parts of POE (polyolefin elastomer), 10-36 parts of halogen-free expanded flame retardant, 10-14 parts of crystal II type ammonium polyphosphate, 11-16 parts of smoke suppressor, 11-21 parts of compatibilizer, 1-3 parts of hollow glass microsphere, 1-4 parts of graphite powder, 1-6 parts of kaolin, 1-9 parts of wood fiber (80-200 meshes), 3-8 parts of kieselguhr (80-180 meshes), 1-9 parts of film-forming assistant, 2-8 parts of acrylic emulsion, 3-7 parts of network interpenetrating emulsion, 1-6 parts of water-based dispersing agent BPS, 1-7 parts of magnesium hypophosphite and 1-3 parts of talcum powder. The invention has the advantages of high safety, high strength, favorable elasticity, light weight, heat preservation, heat insulation, sound absorption and radiation resistance, shortens the building cycle, improves the working environment, enhances the safety coefficient, and reduces the environmental pollution around the building area.