A fiber grating pressure/temperature monitoring device of distinguish range and double sensitivity is developed. Using the Package structure of distinguish range, the pressure measuring range of sensor under the premise of no changing monitoring index of fiber grating is expanded. The size and material of package structure are set to realize the double sensitivity and integration monitoring of pressure and temperature. The monitoring performance of pressure and temperature is tested in experiment, and the results show that the range of pressure measuring is from 0 to 30 MPa, the range of temperature measuring is from 0 ℃ to 150 ℃. Pressure measuring sensitivity are 352.5 pm/MPa and 223.3 pm/MPa respectively under the monitoring range of 0~15 MPa and 15~30 MPa, and linear degrees are 99.42% and 99.33% respectively. Temperature measuring sensitivity are 33.5 pm/℃ and 22.5 pm/℃ respectively, and linear degrees are 99.69% and 99.61% respectively. The proposed monitoring device is simple in structure, which has superior performance and high application value.