A fiber Bragg grating（ FBG） flow velocity sensor based on cantilever with variable width is proposed. By design

the flow velocity sensor which induces the cantilever structure which is made of stainless steel materials and FBG which is tied in the special space of the cantilever. The cantilever structure consists of rectangle and trapezoid and the two parts do not need peg to fix them on

the head of the designed sensor do not need to add any other weight

and the fabrication method is easy. These is a reference FBG

and the experimental results are not affected by temperature changes. Experimental results indicate that there exist a good linear relationship between the drifting of the wavelength of the FBG and flow velocity. Sensitivity of the pro

posed sensor is

and the measuring range of flow velocity sensor is 0

2 m/s approximately. The sensor not only realize compensation of temperature

but also improve measurement precision and sensitivity.