The invention relates to a preparation method of water-based acrylic acid amino baking blue paint for coating stainless steel. According to the prepared water-based acrylic acid amino baking paint, applied self-made water-based acrylic resin has an excellent adhesion force for stainless steel parts and is also excellent in hardness, impact property, flexibility and other properties. The preparation method comprises the following steps of synthesizing water-based hydroxy acrylic resin WR at first, wherein a monomer and an initiator which participate in polymerization are added into a dropping tank, the mixture is stirred and blended uniformly, a solvent is added into a reaction kettle and then stirred, nitrogen is introduced, the solvent is heated to a reaction temperature, the mixture in the dropping tank is completely dropwise added in a certain period of time, the temperature is kept for a period of time, then the initiator is added again, the mixture is completely dropped in a certain period of time, the temperature is maintained for a period of time, cooling is carried out, and then discharging is conducted; putting the water-based hydroxy acrylic resin WR into a paint mixing cylinder, adding a neutralizing agent and water, stirring the mixture for a period of time at a high speed, adjusting the pH value, and separately adding amino resin, a defoaming agent, a leveling agent, a wetting agent, a dispersing agent and water-based blue slurry into the paint mixing cylinder under the condition of high-speed stirring according to a certain proportion; stirring the mixture fora period of time at a high speed, then adding a solvent and water, stirring the mixture for a period of time at a high speed, and conducting packaging after fineness and viscosity successfully pass sampling detection.