This disclosure proposes an automatic circuit board mounting device, including a frame and a
control unit. An adsorption structure, a spreading structure, and a support structure are respectively installed along the top, middle, and bottom of the frame. The
control unit controls the support structure to move upwards so that the first and second support legs of the spreading structure connect with the first and second clips of the clipped plastic parts. Then, it controls the first and second support legs to move laterally in opposite directions to open the first and second clips, forming an mounting space. Next, it controls the adsorption structure to place the circuit board into the mounting space, and after the circuit board is placed or installed, it moves upwards and retracts. After the circuit board is placed, the
control unit controls the first and second support legs to move laterally towards each other to reset. Then, it controls the support structure to move downwards to separate the first and second support legs from the first and second clips of the clipped plastic parts for easy removal of the clipped plastic parts. This automatic circuit board mounting device facilitates automatic circuit board mounting and has a compact structure.