The present invention discloses a fiber fabric flame retardant agent, which comprises the following substances, by weight, 10-20 parts of dicyandiamide, 10-20 parts of polyoxyethelene, 3-6 parts of triethanolamine, 5-8 parts of methylol melamine, 20-30 parts of ethylene glycol, 1-3 parts of sodium tripolyphosphate, 10-20 parts of formaldehyde, and 80-100 parts of water. Compared with the fiber fabric flame retardant agent in the prior art, the fiber fabric flame retardant agent of the present invention has the following advantages that: (1) the fiber fabric flame retardant agent can be used for flame retardant finishing of the fabric, can provide a durable flame retardant effect for the fabric, and has characteristics of simple production process, low raw material cost, and good flame retardation effect; (2) the fabric has an excellent flame retardation performance after washing several times; (3) the fiber fabric flame retardant agent is colorless and transparent, does not contain halogen, does not affect color fastness to daylight, has a soft hand feeling, and does not generate dampening crystallization; and (4) the fiber fabric flame retardant agent has characteristics of no color, transparency, flame retardation, no toxicity, no corrosion, and no pollution.