A position adjusting device includes a movable mechanical arm, suction, an adjusting mechanism, a bottom plate, a first camera, a second camera, and a processor. The processor controls the movable mechanism arm and the suction to move to a top of the first camera in response to a user operation, switches the first camera from a disabled state to the enabled state, acquires the first image captured by the first camera, and calculates a first angle between the first image and a first predetermined image. The processor adjusts the position of a second element based on the first angle and acquires a second angle between a second image of the second element and a second predetermined image. The processor adjusts the position of the second element until the first angle is the same as the second angle when the first angle is not the same as the second angle.