A door structure includes a rotary cover, a pivotal portion and a shielding component. The rotary cover is connected to a housing in a rotatable manner. The rotary cover covers a slot on the housing as rotating to a closed position. The pivotal portion is connected to the rotary cover and passes through a pivoting hole on the housing to be pivoted on the housing so that the rotary cover is capable of rotating relative to the housing. The shielding component is installed on the pivotal portion and disposed inside the housing. The shielding component is for shielding at least one part of the pivoting hole on the housing when the rotary cover rotates to an open position to expose the slot on the housing and the shielding component pivots to a position corresponding to or nearby the pivoting hole with the pivotal portion.