Flow measuring device

The invention discloses a flow measuring device, which comprises a pair of tubular bodies, a confluence three-way joint, a water discharging electromagnetic valve, a liquid level photoelectric sensor and a control system, wherein the tubular bodies are in vertical arrangement, the confluence three-way joint is arranged at the bottom ends of the pair of tubular bodies, the water discharging electromagnetic valve is arranged at the bottom end of the confluence three-way joint, the liquid level photoelectric sensor is arranged on one tubular body in the pair of tubular bodies, the control system is respectively and electrically connected with the liquid level photoelectric sensor and the water discharging electromagnetic valve, and an opening of the upper end of the other tubular body in the pair of tubular bodies is an inlet of liquid to be measured. The flow measuring device can overcome the defects of complicated structure, operation complexity, small application range and the like in the prior art for realiz