Total-separation oil, gas and water multi-phase flow meter

The invention provides an oil, gas and water multi-phase flow meter. The flow meter comprises a waterpower swirler, a gas and liquid buffer tank, a main separation tank, a gas measurement pipeline, an oil phase measurement pipeline, a water phase measurement pipeline and a control system, wherein the gas and liquid buffer tank and the main separation tank are connected with the waterpower swirler respectively; one end of the gas measurement pipeline is connected with the gas and liquid buffer tank, and the other end of the gas measurement pipeline is connected with a downstream pipeline; one end of each of the two liquid measurement pipelines is connected with the main separation tank, and the other end of the liquid measurement pipeline is connected with the downstream pipeline; after a mixture of oil, gas and water is treated by the waterpower swirler, the discharged gas enters the gas measurement pipeline through the gas and liquid buffer tank so that the gas content in the mixed solution can be measured. The discharged oil and water mixed solution enters the main separation tank through a pipeline, and the oil and the water in the mixed solution are separated by the gravity in the main separation tank; the separated oil and water respectively enter the oil phase measurement pipeline and the water phase measurement pipeline so as to be measured; and the measured gas, the measured oil and the measured water enter the downstream pipeline.