Abstract: Disclosed is a single-upright-column mooring type wellhead production operation platform, comprising an upright column body, a positioning and mounting assembly, a rotating table, an oil extraction operation platform and at least one inner well slot, wherein the upright column is of a hollow structure; the positioning and mounting assembly is arranged at a bottom of the upright column body; the rotating table is arranged outside the upright column body, is rotatable around an axis of the upright column body and comprises a mooring connection apparatus; the oil extraction operation platform is arranged on the top of the upright column body and is located above the rotating table, and the oil extraction operation platform is provided with an oil extraction operation assembly; and the inner well slot is arranged in the upright column body and can be connected to the oil extraction operation platform. The platform can adapt to an economic index of extraction of a marginal field.