A projector device is provided. The projector device includes a projector unit, an optical beam splitting module and a first image forming element. The projector unit forms a beam projecting image. The horizontal projection width of the beam projecting image is smaller than the vertical projection width of the beam projecting image. The optical beam splitting module projects one or multiple projection sub-images according to the beam projecting image. The projection sub-images are projected to the first image forming element to form one or multiple projection images. Thus, the projector device obtains multiple projection images from a single image source, and the placement of the image forming elements in the projector unit may be adjusted to obtain the projection images with the best image ratios and the best resolutions. The projector device may be suitable for a head up display.