Modified starch degradable temporary plugging agent and preparation method thereof

The invention relates to a modified starch degradable temporary plugging agent as well as preparation and application methods thereof, and belongs to the field of petrochemical engineering. The preparation method comprises the following steps: S1, adding starch and a solvent into a container device with stirring and heating functions, heating to gelatinize the starch, cooling, adding a copper sulfate solution, homogenizing, adding hydrogen peroxide, reacting, precipitating a product after the reaction is completed, carrying out suction filtration, and drying to prepare powder, so as to obtain oxidized starch; s2, dissolving phenylhydrazine in glacial acetic acid and distilled water to obtain a phenylhydrazine reagent, dissolving oxidized starch in an aqueous solution, mixing with the phenylhydrazine reagent, adding into a container device, heating, carrying out osazone reaction, and after the reaction is finished, drying a product to constant weight to obtain the modified starch degradable temporary plugging