A fiber Bragg grating(FBG) pressure transducer model is proposed based on the thin wall canister in order to improve the sensitivity of the FBG pressure sensor.The principle of the model is analyzed wtih elasticity theory.The relationship between the elastomer stain and the pressure is also derived,and it shows that the pressure amplification coefficient of the FBG sensor can be enlarged by changing the ratio of inner radius and outer radius or geometry size.The numerical calculation is carried out by using 3J53 as elastomer.The result shows that the pressure resolution at 70 MPa is 44 pm/Mpa,which is 14 times than the naked FBG pressure sensor.