The invention discloses a canvas capable of improving a flame retardant property. A polyester canvas with high strength is adopted as base cloth; a flame retardant layer is coated on at least one surface of the base cloth, and is prepared from the following raw materials in parts by weight: 3 to 10 parts of glycidyl methacrylate, 3 to 5 parts of acrylic acid-2-ethyl propyl ester, 1 to 8 parts of polyethylene glycol oleate, 2 to 4 parts of polydimethylsiloxane, 1 to 6 parts of tricresyl phosphate, 1 to 4 parts of diethylaminoethyl methacrylate, 1 to 6 parts of diethylene glycol divinyl ether, 0.5 to 2 parts of 2,3-dimercapto-1-propanol, and 1 to 4 parts of 2-methyl-5-oxocyclopentyl-1-enyl propionate. Therefore, a final product has excellent flame retardance and waterproofness.