An optical evanescent wave coupling temperature sensor based on evaporating Cu f ilm onto tapered photonic crystal fiber is proposed.The temperature sensor is prepared by fusing a length of 20mm photonic crystal fiber between two sections of single-mode fiber,evaporatin g a layer of Cu film onto the tapered photonic crystal fiber after the photonic crystal fiber has been fus ed and tapered.The discharge current of fusion splicer is 10mA,the speed of optic fiber tapering i s 0.08mm/s,and the hydrogen flow rate is 160mL/min.After tapering the photonic crystal fiber,the smallest diameter of photonic crystal fiber waist is 68.47μm and the interference fringe contrast of this sensor is up to 8dB.The fabricated sensor is placed in the temperature control cabinet for temperature sensing expe riment,with both ends of the sensor with a broadband light source and a spectrometer,respectively.The e xperimental results show that when the tapered length is 10mm and the Cu film thickness is 110nm, the highest temperature sensitivity is 0.075dB/℃ in the 30－80℃ range.This t emperature sensor has the advantages of compact structure,easy manufacturing,high sensitivity,so i t can be used in industrial production,biological medicine and power electronics .