A self-mounted deep draught production oil-storage platform comprises a floating body, an oil production treatment module, a platform drilling machine, an extending shell structure and an annular structure, wherein the oil production treatment module is arranged at the upper part of a floating body technical deck; the platform drilling machine is arranged at the upper part of the floating body technical deck; the extending shell structure is arranged at the lower part of the floating body and is formed by extending downwards; and the annular structure is arranged under the extending shell structure; the cross section of the extending shell structure is consistent with that of the floating body; an opening is formed in the bottom of the extending shell structure; the opening is in communication with seawater; the upper part of the annular structure is connected with pile legs; and the pile legs are connected with the floating body through gear devices arranged on a main deck. The self-mounted deep draught production oil-storage platform has the advantages that the platform can be self-mounted so that the development costs of marginal oil fields are greatly lowered; and moreover, drilling and workover, oil production, production and treatment, storage and outward transportation and life support are integrated so that the production efficiency is greatly enhanced; and the self-mounted deep draught production oil-storage platform is very suitable for developing the marginal oil fields with large water depths and small reserves.