Optical storage system is the key role for the future all-optical communications and computer. Through numerical study, we design a new kind of magneto-optical storage system based on the coupling of one-way edge modes of magneto-optical photonic crystals and microcavity modes. A close field circulation loop is achieved from the one-way edge modes. By designing a magnetic cavity and another edge waveguide, we can not only take out the signal from the loop but also write the signal into the loop. Through controlling the magnetic field on the cavity, we can dynamically achieve the operation of reading and writing of electromagnetic signals.