A novel flow velocity sensor based on a chirped fiber Bragg grating (CFBG) that includes the chirped fiber grating pressure sensing setup and Venturi tube has been proposed, aiming to increase the size and reduce the cost of the sensor system.The CFBG-b ased intensity-modulated sensor shows the potential applications in various sensing areas due to their many advantages.The relationship between the flow velocity and the bandwidth of the reflection spectrum of the chirped fiber Bragg grating is derived.The deformation of the rectangular cantilever beam is caused by the pressure on two sides of the cross section of the aluminum foil tube in the pressure sensing setup,and it results in the bandwidth change of th e reflection spectrum of the chirped fiber Bragg grating that is mounted at the side of the c antilever.The flow velocity can be obtained by measuring the bandwidth of the reflection spectrum o f the chirped fiber Bragg grating,which is not sensitive to the temperature.The experimental results verify the feasibilit y of the proposed sensor with a measurement range from 8to 100mm/s.