The utility model discloses a combined bridge deck structure reinforced by flat-bulb steel. The device comprises an upper combined component and a lower combined component, the upper combined component comprises a bridge deck slab, flat-bulb steel and an upper transverse partition plate. One end of the flat-bulb steel is fixedly connected to the bridge deck; an opening for the flat-bulb steel to pass through is formed in the upper transverse partition plate; the flat-bulb steel penetrates through the opening and is fixedly connected with the upper transverse partition plate, the opening comprises an upper notch and a lower notch which are communicated with each other, the upper notch is formed in one side edge of the upper transverse partition plate, the opening width of the upper notch ismatched with the web thickness of the flat-bulb steel, the opening width of the lower notch is larger than the bulb thickness of the flat-bulb steel, and the upper transverse partition plate is fixedly connected with the lower combined component. The utility model further discloses a bridge structure adopting the combined bridge deck structure. According to the utility model, the flat-bulb steelis used as the stiffening rib, so that the flat-bulb steel is connected with the two sides of the upper diaphragm plate, the assembly sequence of the diaphragm plates is improved, and the quality of welding seams among the diaphragm plates, the bridge deck slab and the flat-bulb steel is improved.