A computer-implemented method for component arrangement in a PCB layout device is provided. The device includes wiring diagrams. First, generates a PCB encapsulation diagram corresponding to the selected wiring diagram. Then, obtains the coordinates of each electronic component in the selected wiring diagram. Next, generates a prompt to prompt the user to select a reference point in the PCB encapsulation diagram. Then, obtains the coordinates of the reference point. Next, determines an abscissa difference and an ordinate difference between one component in the wiring diagram and the reference point. Then, determines the coordinates of each encapsulated component in the PCB encapsulation diagram according to the abscissa difference, the ordinate difference, and the coordinates of each electronic component in the wiring diagram. And last, moves each encapsulated component to the determined corresponding coordinates of each encapsulated component in the PCB encapsulation diagram.