The invention discloses a weighing water level gauge which comprises an amphibious coaxial shaft, a sensing unit for measuring the buoyancy of the amphibious coaxial shaft, a case and a supporting pile. The case is arranged at the upper end of the supporting pile; a first magnetic steel is arranged in the case; a cross beam is arranged at the lower end of the supporting pile and is provided with a fourth magnetic steel; a shaft hole is arranged at the lower end of the case; the amphibious coaxial shaft passes through the shaft hole and does not contact the hole wall of the shaft hole; the upper end of the amphibious coaxial shaft is arranged in the case and contacts the bottom of the case; a contact face of the amphibious coaxial shaft with the case is provided with a force sensor of the sensing unit and the upper end and the lower end of the amphibious coaxial shaft are respectively provided with a second magnetic steel and a third magnetic steel; and the four magnetic steels are arranged coaxially and have axes vertical to water level. The whole weighing water level gauge can be fixed conveniently and easily; the upper end of the amphibious coaxial shaft is in contact with the case without friction force under the combined action of gravity, buoyancy and bearing force; by using four magnetic steels for axial positioning, the weighing water level gauge avoids shaking of the amphibious coaxial shaft and can achieve high water level measurement accuracy.