Air hole in photonic crystal fiber(PCF) cladding is filled with magnetic fluid(MF). Tuning and sensing of PCF optical properties can be realized by using the refractive index tunable property of MF. The effects of filling MF on the mode and loss characteristics of PCF are analyzed with full vector finite element method. The influences of structural parameters on loss sensitivity of the circular hole PCF filled with MF are analyzed. The loss sensitivity characteristics of circular hole and elliptical hole PCFs filled with MF are compared, and the temperature and magnetic field characteristics of elliptical PCF filled with MF are investigated. Simulation results show that fiber mode effective refractive index, mode area and loss of PCF are increased by filling MF. The loss sensitivity caused by the change of MF refractive index in elliptical hole PCF is about 4 times of that of circular hole PCF. The temperature and magnetic sensitivities of elliptical air hole PCF filled with MF are -0.279 dB/℃ and 0.06 dB/Oe (1 Oe1000/4π A/m), respectively. It provides reference for the design of novel high sensitivity fiber.