In order to meet the demand of current monitoring in power equipment,a long period fiber grating (LPFG) optical current sensor based on magnetic fluid was proposed in this paper. The change of external magnetic field can cause the change of medium-high frequency refractive ind ex and the resonant wavelength of LPFG is affected by the environmental refractive index.T he LPFG package structure is placed in a magnetic field environment around an energized conductor, and the measured current can be obtained by measuring the wavelength shift of th e LPFG. Experimental results show that the current sensor is feasible and stable,and it s sensitivity is about －2.3nm/A.The sensor has the advantages of simple structure,high sensiti vity,good anti- interference performance,small volume,no hysteresis effect,and easy to be int egrated with power equipment.It has a broad application prospect in the current monitoring o f power system.