A non-intrusive flow test method based on turbulent vibration principle is proposed. The method wounds a specific length of sensing fiber tightly around the outer wall of a pipe and connects the optical fiber gratings at both ends,then the sensing fiber and the optical fiber gratings compose a flow sensing unit. When the fluid flows through the pipe, the dynamic pressure is generated by the turbulence, and the dynamic pressure causes the light phase shift of the sensing fiber to change. The phase information is demodulated by the fiber optic interferometer technology, time division multiplexing technology and phase generated carrier modulation and demodulation techniques, and the flow was detected in line. The experiments show the relationship between phase change and flow rate is a quadratic curve and the fluid flow monitoring range of the experimental system is from 5 m3/h to 50 m3/h. As the optical fiber is to be a flow sensing signal, the method is characterized by a simpler structure, higher sensitivity. It overcomes the shortcoming of an optical fiber sensing flowmeter in intrusive flow, and is an idea real-time monitoring method of flow for oil well logging.