The utility model discloses a multifunctional measuring tank. The multifunctional measuring tank comprises a skid-mounted box body, wherein the inner part of the skid-mounted box body is divided into a liquid charging chamber, an oil-water mixing chamber, an oil storage chamber and a water storage chamber, wherein the liquid charging chamber is connected with a liquid charging pipeline, a settled grit discharging opening is formed at the bottom of the liquid charging chamber, the liquid charging chamber is provided with a discharging opening which is communicated with the oil-water mixing chamber, a weir plate is arranged between the oil-water mixing chamber and the oil storage chamber, and is lower than weir plates of other chambers, the oil-water mixing chamber is provided with a water discharging opening which is communicated with the water storage chamber, the oil storage chamber and the water storage chamber are respectively provided with an oil discharging opening and a water discharging opening, the oil-water mixing chamber is provided with a liquid level measuring device which is connected with an electric pump and a control box, flowmeters are respectively arranged at each discharging opening, an expiring hole and a pipeline are arranged at the top of the measuring tank, the expiring hole is used for discharging gases, and the pipeline is connected with the expiring hole. The multifunctional measuring tank has the comprehensive functions of separation, heating, grit removal and measurement, and has the advantages of convenience and quickness for operation and low investment in equipment cost.