The invention relates to the technical field of synthetic resins and plastics, and concretely relates to a preparation method of a novel nontoxic gallic acid epoxy resin stabilizer. The preparation method of the novel nontoxic gallic acid epoxy resin stabilizer comprises the following steps: adding gallic acid, chloropropylene oxide and a phase transfer catalyst into a 250 mL four-mouth flask provided with a spherical condenser tube, a thermometer and a stirring device, stirring and heating above substances to 100 DEG C, carrying out a constant temperature reaction for 5-6 h, and cooling the obtained reaction product to room temperature; adding 0.40 mol of a NaOH solid in batches, and carrying out a reaction at 67-70 DEG C for 1-2 h; and steaming out excess chloropropylene oxide, cooling the steamed chloropropylene oxide, carrying out pumping filtration, and washing obtained solid to obtain a pale yellow nontoxic gallic acid epoxy resin solid.