The invention discloses an optical fiber current transformer based on magnetostrictive effect. The optical fiber current transformer comprises a wideband light source, a coupler and an optical fiber grating sensing probe which are sequentially connected. An edge filter, a photoelectric probe, a demodulation circuit and a remote data processing terminal are sequentially connected to the coupler. The optical fiber grating sensing probe is an optical fiber magnetostrictive sensing probe. The optical fiber current transformer is resistant to electromagnetic interference, fast in response, wide in measuring band, good in insulation, small in size, convenient to mount and adaptive to the intelligent, digital and network requirements of current power systems.