The utility model discloses an integrated high-density fuel tank, and belongs to the field of auto parts. The integrated high-density fuel tank comprises a fuel tank main body and an oil detecting sensor which is arranged on the fuel tank main body, wherein the fuel tank main body comprises an oil storage tank, an oil filling passage arranged on the oil storage tank and an oil filling port connected to the oil filling passage; a vertical pillar which is symmetrical with the oil storage tank in height is arranged on the oil detecting sensor; a plurality of reed pipes are uniformly distributed in a height direction of the vertical pillar; a float which can move up and down sleeves the vertical pillar; a magnet for inducing the reed pipes is additionally arranged on the float; the oil filling port is of a funnel-shaped structure, and the oil filling port and the oil filling passage are integrally formed and welded on the oil storage tank; the cross section of the vertical pillar is rectangular; the cross section of a bushing hole of the float is rectangular as well. The integrated high-density fuel tank disclosed by the utility model is simple in structure; the fuel tank can not only precisely monitor oil consumption but also reduce production cost and the consumption of welding wire materials during manufacturing; the integrated high-density fuel tank is energy-saving and environment-friendly.