A multiplexed fiber-optic sensor combining the advantages of extrinsic Fabry-Perot interferometer (EFPI) and fiber Bragg grating (FBG) is presented for simultaneous stress and temperature measurement. Ultra-high-vacuum magnetron sputter system, electroplating technology, and laser welding technology are adopted to realize fiber sensor encapsulation without adhesives, which can improve the resistance to elevated temperatures of the sensor. Experimental results show that the sensor has a stress sensitivity of 90 pm/N and a linearity of 0.9965 at the temperature of 290 ℃. FBG of the multiplexed sensor has a temperature sensitivity of about 12 pm/℃ and a linearity of about 0.9988. Broad applications based on the metal packaged multiplexed fiber optic EFPI-FBG sensor at higher temperature in this work can be expected.