In this article, we propose a simple method to increase the pressure sensitivity of a typical fiber Bragg grating (FBG) while decreasing the temperature sensitivity. This method uses a typical FBG, which is coated with a thick layer of polymer with two symmetric air channels. By this method the pressure sensitivity can be increased (e.g. 1.1×10-5 /MPa) while the temperature sensitivity is negligible (e.g. -0.174×10-8/oC) by proper selection of the geometrical parameters and material types of the sensor.