Photonic crystal fiber (PCF) has many characteristics which are different from those of traditional optical fiber, and the application of PCF in sensing field becomes a hot research topic in recent years. The basic structure, guiding principle and preparation method of PCF are introduced. The principle and research progress at home and abroad of interference, absorption, fluorescence, surface plasmon resonance, Raman scattering and grating PCF sensors are summarized. The application fields, advantages and disadvantages of PCF are analyzed. The development trend of PCF sensors is prospected.