A new method of producing a fiber-optic Fabry-Perot Interferometer (FPI) for high-temperature sensing is presented. The sensor is fabricated by fusion splicing a short section of Endlessly SIngle-mode Photonic Crystal Fiber (ESM-PCF) to the cleaved end of a Single-mode Fiber (SMF) with an intentional complete collapse at the splice joint. Compared with the existing PCF-based FPI sensors, the FPI sensor fabricated by using the simple method have a stable sinusoidal interference fringe with higher interference light intensity. The high-temperature response of the FPI sensor was experimentally studied and the results show that the sensor allows liner and stable measurement of temperatures up to 1 100 ℃ with sensitivity of ~29.4 nm/℃, which makes it very attractive for aeronautics and metallurgy areas.