The application provides a steel pipe, its preparation method and application. It includes: dosing according to the following chemical composition to obtain raw materials: by weight percentage, the raw materials include C 0.08-0.30%, Si≤0.5%, Mn≤1.0%, Cu 0.5-2.0%, Al≤1.0%, Ce 0.01 ~0.2%, Cr 0.5~1.5%, Mo 0.5~1.5%, V≤0.3%, N≤0.005%, O≤0.005%, S≤0.005%, P≤0.005%, the balance is Fe; Melting, pouring, electroslag remelting, rolling and heat treatment to obtain steel pipes, when the contents of O and S in the reaction product system are not greater than 0.005wt%, Ce is added. The steel pipe prepared by the above method has the advantages of high strength, high toughness, resistance to sulfide stress corrosion and microbial corrosion, and realizes the integration of structure and function.