The invention discloses a waterproof and flame-retardant paper cone, belonging to the technical field of electroacoustic products. The slurry of the paper cone is prepared by mixing and sitrring the following main raw materials in parts by weight: wood pulp, sisal hemp, cotton pulp, kapok, bulletproof fiber, wool, glass fiber, a dye, table salt, a hardening agent, a flexibilizer, a regulator, a waterproofing agent and a flame retardant, wherein the waterproofing agent is prepared through the following steps: adding acrylic rubber latex, hydroxyethyl cellulose, bentonite and sodium metasilicate according to a weight ratio of 1: (0.1-0.5): (0.2-0.5): (0.05-0.2) into water, carrying out mixing under stirring so as to form an emulsion, placing the emulsion in a stirring reflux device, and carrying out a reflux reaction for 3 to 4 hours; and the flame retardant is prepared by uniformly mixing kaolin with decabrominated dipheny ethane and antimonous oxide or magnesium hydroxide with a weight ratio of 1: (1-5) under stirring. The waterproof and flame-retardant paper cone provided by the invention has subdued sound effect and good dampproof and waterproof performances, flame retardance and mechanical performance, and is improved in use safety and prolonged in service life.