SD card data storage unit for ship and storage protection method

The invention relates to an SD card data storage unit for a ship and a storage protection method. The SD card data storage unit for the ship is installed on a metal electrical device, an SD card slot opening is formed in the rear portion of the metal electrical device, an SD installing base is installed corresponding to the SD card slot opening, an SD card slot is installed in the SD installing base, an SD card shielding cover is installed on the rear portion of the SD installing base, an SD card is inserted into the SD card slot, sealing press fit is carried out on the SD card slot opening through a conductive gasket, an SD card cover plate and screws, continuity of electric conduction of the SD card data storage unit and the metal electrical device is ensured, an isolating power source and data bus isolation are arranged between an SD card driving circuit and the SD card, and dividing configuration is carried out on an SD storage area. When the metal electrical device is replaced or updated, only the SD car