A flash memory disk includes a holder, a plug, a housing and a pulling ring. The plug is joined with the holder and exposed out of the holder. The housing has a containing space for accommodating the holder and the plug, wherein two sides opposite to each other respectively have a through sliding groove and the third side of the housing there has an opening. The two arms of the pulling ring have sliding blocks, and the sliding blocks are moveable and matched with the through sliding grooves, wherein the pulling ring is rotated about the axis connecting both the sliding blocks, and when the sliding blocks of the pulling ring is moved, the holder would be located between a first position where the plug is entirely accommodated in the containing space and a second position where the plug is entirely protruded out of the opening.