Abstract: The mechanical properties and microstructure analysis were investigated for a new high steel grade super deep well oil casing and evaluated by the relevant standards in China and abroad. The results show that the microstructure of the new oil casing is Fe-Cr-Ni solid solvent, adding alloy element Mo, V can effectively regulate the toughness and strength of the new oil casing. The longitudinal impact word is 115 J at 0 ℃ and the tough and brittle transition temperature is -68 ℃. The transverse impact work is 99J at 0 ℃ and the tough and brittle transition temperature is-65 ℃. At room temperature the longitudinal yield strength is 915 MPa and the transverse yield strength is 1012 MPa.