The invention relates to an unconditional stability equipped deep-draft floating production platform and an offshore installation method thereof. The unconditional stability equipped deep-draft floating production platform is characterized by comprising an annular ballast tank at the bottom, a plurality of columns with small cross sections, an annular buoyancy tank at the middle part, a pluralityof columns with large cross sections, a drilling machine on the upper part and an oil gas processing module. The ballast tank adopts a permanent fixed ballast mode, and the tank is internally filled with weights to ensure that the buoyant center of the platform is higher than the gravity center; the columns with large and small cross sections are uniformly arranged on the buoyancy tank and the ballast tank respectively, and the lower parts thereof are respectively integrated with the buoyancy tank and the ballast tank; each column with a large cross section is provided with a central pore canal axially; a lower part in the central pore canal is provided with a chopping board connection structure with a groove; after the construction is completed, the columns with small cross sections are inserted into and pass through the central pore canals of the columns with large cross sections correspondingly; the platform is in a folding state; each column with a large cross section is provided with a group of mooring cables; the drilling machine and the oil gas processing module are installed in the construction area; the equipment is entirely transported to the installation site by adopting a dry haulage or wet haulage method and then is installed. The platform in the invention can be applied to deepwater oil and gas exploitation in the condition of threatening marine environment.