The invention provides an amphiphilic block T-shaped copolymer and a preparation method thereof, belonging to the field of petroleum exploitation technology. The amphiphilic block T-shaped copolymer comprises at least one block (A) taking acrylamide as a monomeric unit, at least one block (B)at least one block (A) taking alkylphenol polyoxyethylene ether as a monomeric unit, and at least one block (C) taking 2-acrylamide-2-methylpropanesulfonic acid as a monomeric unit. When being adopted as an oil displacement agent, the amphiphilic block T-shaped copolymer is less influenced by outside metal ions, and has excellent salt resistance, a T-shaped structure can form a reversible supermolecule aggregation network structure with intermolecule association, so that the temperature resistance and salt resistance properties of the polymer can be effectively enhanced.