The invention discloses a thermoplastic elastomer for profile control and water plugging. The thermoplastic elastomer is prepared from the following raw materials by weight: 8-10 parts of a componentA, 1-3 parts of strong acid, 1-3 parts of a hydrophobic modifier and 100-105 parts of water; wherein the component A is any one of polyethylene glycol, polyvinylmethyl ether, polyvinyl alcohol and a copolymer of acrylamide and acrylonitrile; the strong acid is any one of concentrated hydrochloric acid and concentrated sulfuric acid; the hydrophobic modifier is any one of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, beta-propiolactone, gamma-butyrolactone, delta-valerolactone, methyltriacetylsilane, methyltrimethylsilane, butyl acrylate and ethylene glycol dimethacrylate. The thermoplastic elastomer for profile control and water plugging has the advantages of one time preparation molding, high deformation capacity, temperature and salt resistance, high stability and the like,and is suitable for large-scale production and application.