The invention belongs to the technical field of a peroxide stabilizing agent and particularly relates to a stabilizing agent in a urea peroxide storage process and a preparation method of the stabilizing agent. The stabilizing agent in the urea peroxide storage process provided by the invention comprises the following material ingredients in parts by weight: 5 to 20 parts of water absorption agents, 5 to 15 parts of flow aids, 5 to 20 parts of heat resistance agents and 40 to 80 parts of solid active oxygen stabilizing agents, wherein the water absorption agents are one kind of materials of magnesium chloride, calcium chloride or sodium chloride or a mixture of the magnesium chloride, calcium chloride and sodium chloride, the flow aids are one kind of materials of magnesium carbonate, light magnesium carbonate, potassium stearate, microcrystalline cellulose, superfine silica powder or tricalcium phosphate or a mixture of magnesium carbonate, light magnesium carbonate, potassium stearate, microcrystalline cellulose, superfine silica powder and tricalcium phosphate, the heat resistance agents are one kind of materials of potassium sulfate, potassium chloride or potassium nitrate or a mixture of potassium sulfate, potassium chloride and potassium nitrate, and the solid active oxygen stabilizing agents are one kind of materials of sodium tripolyphosphate, sodium fluoride, sodium borate and sodium silicate or a mixture of sodium tripolyphosphate, sodium fluoride, sodium borate and sodium silicate. Products provided by the invention have a long quality guarantee period, the bag expansion is avoided, the agglomeration is avoided, the in-site use is convenient, the product flowability is good, and the application range is wide.