Based on additive manufacturing technology, this paper studies and fabricates a new FBG pressure sensor by changing additive manufacturing parameters including infill densities, infill model sizes, and infill materials. The test results show that the shrinkage strain and tensile strain of infill materials change evenly during encapsulation of FBG sensor. Three functions including the upper bound function-f(x)= -9E-08x 3+0. 000 4x 2-0. 709 8x+368. 86, the lower bound function-f(x)= -1E-08x 3 -3E-05x 2 +0. 096 4x-235. 95, and the residual function-f(x)= -5E-09x 3+1E-04x 2-0. 653x+712. 9 are defined respectively in term of the strain characteristics inside the printing model. The calibration test and stability test of the sensor prove that the FBG pressure sensor has good linearity and stability. When the infill densities of the FBG pressure sensor was 20%, 40%, 60%, 80% and 100% respectively, and the infill material and infill size were kept the same as the Carbon Fiber material and the cube model (35 mm×35 mm×10 mm), the sensor’s sensitivities was found to be 0. 69, 0. 45, 0. 39, 0. 21 and 0. 19 pm/ kPa, respectively, the sensitivities decrease with the increase of infill density. When the infill model is cylinder with diameter of 60 mm and thickness of 6 mm (60 mm×6 mm) and the cylinder (60 mm×15 mm) respectively, and the infill material and infill density was kept same as Carbon fiber and 20% respectively, the average sensitivities of FBG pressure sensors with thickness of 15 mm and 6 mm respectively are 0. 59 and 0. 18 pm/ kPa respectively. When the infill material is carbon fiber (CF) and Polylactic Acid (PLA) respectively, and the infill density and infill size was kept same as 20% and cylinder (60 mm× 15 mm) respectively, the average sensitivities of FBG pressure sensors made by PLA and CF respectively are 16. 26 and 0. 59 pm/ kPa respectively. Therefore, FBG pressure sensors of different sensitivity can be obtained by changing the infill density, infill material, and the size of infill model.