The invention discloses a feeding device of a flexible printed circuit (FPC) board and a keyboard base plate automated assembly system. The feeding device of the FPC board comprises a lifting material platform, a lengthways material moving mechanism and a material absorption frame which is connected with a sliding table, wherein a material box which is used for arranging the FPC board in a stack mode, the lengthways material moving mechanism comprises a lengthways slide and the sliding table which is in sliding connection with the slide, and the material absorption frame is arranged above the lifting material platform. By the adoption of the lifting material platform, the fact that the FPC board with multiple layers automatically feed the material to the position is achieved, only the whole box is needed to be changed, in the process of a robot continue assembling, the change of the material box of the FPC board has no need to be operated in a machine stopped state, reloading time is saved, and the production efficiency is improved. The keyboard under plate automated assembly system achieves assembling of each element by the adoption of the robot, the quantity of automatic control unit is reduced, and the floor area of the whole automated assembly system is benefitted to be reduced.