The invention discloses a steel-concrete structure exploitation and reservation platform for developing and producing marine oil. The steel-concrete structure exploitation and reservation platform comprises an upper steel-structure deck plate; a middle steel-structure process tank, which is fixedly connected with the upper steel-structure deck plate, is arranged below the upper steel-structure deck plate; a lower steel reinforced concrete sinking box, which is fixedly connected with the middle steel-structure process tank, is arranged below the middle steel-structure process tank; a bottom steel-structure hem, which is fixedly connected with the lower steel reinforced concrete sinking box, is arranged below the lower steel reinforced concrete sinking box; a ballast tank and a crude oil tank are arranged in the lower steel reinforced concrete sinking box. According to the steel-concrete structure exploitation and reservation platform disclosed by the invention, a structure of arranging the steel-structure process tank in the middle is adopted; compared with a concrete-structure platform, the weight of the platform and the depth of draft are effectively reduced; the steel-structure hem is additionally arranged at the bottom, so that the anti-washout, anti-slippage and anti-overturning capabilities of the platform are improved; the buoyancy of the platform in water is increased, and the foundation processing difficulty and the marine engineering quantity are reduced; the requirements on construction sites and fairway depths are reduced; meanwhile, the investment cost and the post-period maintenance cost are reduced.