Solid internal pressure is one of the important parameters in traffic bridge and defense field.However, the existing testing equipments have the defects of serious electromagnetic interference, poor reliability, and poor accuracy.To overcome the above problems, a fiber bragg grating (FBG) high pressure solid pressure sensor which used thin plates as elastic bearing diaphragm and applied the deflection under pressure to pull the pressure sensitive grating to realize pressure sensing axial displacement was designed.By calculating on the structure according to the measurement range and finite element simulation, its feasibility was confirmed.In the laboratory with constant temperature, the pressure calibration experiment was carried out, and the temperature compensation was performed by the temperature compensation grating in the same temperature field to correct the temperature drift of strain grating.Experimental results showed that the newly devised FBG pressure sensor could sense the pressure as high as 50 MPa, with a linearity of 99.2%.