Optical fiber grating temperature and pressure sensor based on diaphragm with temperature compensation is described.Elastic diaphragm acts as pressure sensing element

axial displacement occurs under pressure and compress pressure sensing grating to realize pressure sensing.Temperature compensation and active correction by add another temperature grating are adopted simultaneously to eliminate the thermal errors for the pressure grating.Besides

the temperature grating also is used for measuring temperature.Pressure and temperature characteristics of the sensor are measured.The experimental result shows that pressure sensitivity is 528 pm/MPa and temperature sensitivity is 8 pm/℃.