A novel high sensitivity fiber Bragg grating(FBG) pressure sensor was brought forward based on columned vessel and piston.FBG was stuck to the fundus material by high intension pastern.Fundus material was fixed between the piston and the bottom of columned vessel.The pressure variation in the columned vessel results in the motion of the piston and drives the change of the tension in the FBG,then the external pressure can be measured by testing the reflective wavelength of FBG.The theoretical and experimental pressure sensitivity coefficient of the proposed sensor are 0.92 nm/MPa and 0.822 3 nm/MPa,which are 306 and 274 times of that of the bare FBG respectively.The FBG sensor has good linearity,and the correlation is 0.999 8.The pressure sensitivity can be changed by changing the size of fundus material and the area of piston to meet the measurements of different pressure ranges.