A paper pickup structure of a paper feeding device is provided. The paper pickup structure includes a rotating arm, including a connection portion, a base, and a combination member, in which the connection portion and the combination member are located on the base, a first gear, combined with the connection portion to be switched between a forward rotation state and a reverse rotation state, so as to drive the rotating arm to rotate, a limiting member, located on the rotating arm, in which one end of the limiting member is combined with the combination member of the rotating arm, or one end of the limiting member is separated from the combination member through the rotation of the rotating arm, a second gear, located on the base, and a third gear, driven by the second gear to rotate when the rotating arm rotates to a predetermined position.