In this paper, a high-sensitivity temperature and pressure sensor is designed. It utilizes a diaphragm to transfer pressure to a double-hinged lever structure and adopts a fiber Bragg grating (FBG1) as the strain sensor to measure pressure. The introduction of the double-hinged lever effectively improves the sensor's pressure measurement sensitivity. The sensor's measuring range is 0-18 MPa and the sensitivity is 453.16 pm/MPa. At the same time, another fiber Bragg grating (FBG2) is pasted on the lever to eliminate the temperature influence in the pressure measurement process and realize the simultaneous measurement of temperature and pressure. The sensor's temperature sensitivity is 10.41 pm/°C in the 25-65 °C range. Due to their anti-electromagnetic interference characteristics, optical fiber sensors are commonly used to measure temperature and pressure in harsh environments.