The invention discloses an aqueous solution type lithium iron phosphate positive electrode adhesive, and a preparation method and application thereof. The aqueous solution type lithium iron phosphatepositive electrode adhesive is an aqueous solution, and the solid content is 3-15%; at 25 DEG C, the viscosity of the aqueous solution type lithium iron phosphate positive electrode binder is 5000-100000 cp, and the pH value is 6-8; the aqueous solution type lithium iron phosphate positive electrode adhesive comprises the following components in parts by mass: 10-20 parts of low-grade unsaturatedcarboxylic acid, 8-15 parts of acrylamide and derivatives thereof, 5-20 parts of water-soluble acrylate, 5-10 parts of (methyl) acrylate phosphate ester, and 0.1-0.4 part of initiator. Compared with the prior art, a single-component aqueous solution system is adopted, compared with a multi-component blending solution, the storage and use stability is better, the formula is simpler, and preparationis easy and convenient; in the aspect of components, acrylic acid, acrylate, acrylamide and other monomers are adopted for copolymerization, and the product has better thermal stability than polyvinyl alcohol, CMC and other water-soluble polymers.