The invention discloses a flame-retardant building coating and a production method. The flame-retardant building coating is prepared from the following raw materials: polyurethane, an emulsion, glassfiber, water, a composite coupling agent, a flame retardant, pigment, an antifoaming agent, a wetting agent and a leveling agent. The flame-retardant building coating disclosed by the invention can improve such performance of a film as surface performance, mechanical and optical performance, corrosion resistance, dirt clearing performance and flame retardance, enhances the water repellency, dustadsorption preventing performance and self-repairing function of the coating, and further improves the film in density, toughness, weather resistance, permeation resistance, fire resistance, expansionproperty and the like; moreover, the flame-retardant building coating prolongs the fire-resistant time, reduces the porosity of the film, prevents bacteria from adhering to the film, and clears pollutants on the film surface so as to purify the environment.