The invention relates to a high-strength high-water-absorption degradable plugging agent and a preparation method thereof. The plugging agent is prepared from the following raw materials: an alkenyl
monomer, a hydrophilic auxiliary agent,
modified starch, a cross-linking agent, an initiator, an inorganic reinforcing agent, a degradation auxiliary agent and a degradation activator, wherein based onthe total
mass of the raw materials, the content of the alkenyl
monomer is 15-30%, the content of the hydrophilic additive is 10-30%, the content of the
modified starch is 20-45%, the content of thecross-linking agent is 0.05-1.5%, the content of the initiator is 1.5-2%, and the content of the inorganic reinforcing agent is 2-5%. According to the invention, the high-strength high-water-absorption degradable plugging agent contains a plurality of hydrophilic groups, so that the plugging agent is high in water
absorption rate and elasticity, is flexible gel, has deformability, can be squeezedinto a leakage channel to be compacted, is high in pressure bearing strength, contains high-temperature-resistant alpha-
amylase, is subjected to
degradation reaction at high temperature to destroy a plugging agent framework, is slowly liquefied, is free of residues and is free of
pollution to stratums.