Magneto optical switch is widely used in high-speed all-optical communication network. Normally, it is composed of PBS (polarization beam splitter), FR (Faraday rotator), displace (polarized light separator) and PBC (polarization beam combiner). MEISU's Magneto-optical switch uses faraday magneto-optical effect for optical switching. Currently, the types of magneto-optical fiber. The CrystaLatch™ Solid-State Fiber Optic Switch family features fast response and ultra-high reliability exceeding 100 billion cycles. The primary advantage is the ability to handle large beam cross. An all-fiber magneto-optic switch is designed in this paper, which makes use of Faraday Effect, fiber-type polarizing beam splitter/combiner (PBS/PBC), magneto-optic crystal fiber, nanosecond impulser and high-speed magnetic field control technology.