Three-phase flow measuring device

The invention provides a three-phase flow measuring device which comprises a main pipeline used for conveying the mixture of oil, gas and water, a Venturi device which is arranged on the main pipeline and used for measuring the flow of the liquid in the main pipeline, a conductivity measuring sensor which is arranged in the main pipeline and used for measuring the gas phase fraction of small bubbles, the phase fractions of the oil, gas and water phase and flowing speeds of gas and liquid, a capacitance measuring sensor which is arranged in the main pipeline and used for measuring the gas phase fractions of big and small bubbles, the phase fractions of the oil, gas and water phase and the flowing speeds of gas and liquid, as well as a gamma densimeter which is arranged in the main pipeline and used for measuring the density of the mixture. The three-phase flow measuring device can correctly measure the moisture content of the condensate oil of the high-pressure condensate gas well and realize the on-line monitoring of the oil-gas well, thus being more applicable to practices.