Abstract: In the oil well logging, fluid flow is an extremely important parameter which determines the transmission characteristics of the oil production. A new type of flowmeter based on non-intrusive fiber optic interferometer was proposed.The fiber optic sensors wrapp closely around the outside wall of the pipe, and when fluid flows through the pipe, the vibration of pipe can be induced by turbulent flow,which results in the changes of dynamic pressure ,and then leads to the changes of light phase, so the relevant flow may be obtained from measuring these changes. The frequency characteristic of the pipe-s vibration signals was found in experiment,then the fixed relationship between the standard deviation of the pipe wall-s vibration acceleration impulse value induced by turbulence and the average fluid flow was determined, and the experiment acommplished fluid flow monitoring whose rang was from 5 m3/h to 50 m3/h.