The present invention relates to an optical engine of a projection television in which a path of illumination emitted from a light source is aligned to correspond with the image producer by turning a screw of a mirror device. The object of the present invention can be achieved by an optical engine of a projection television including a light generator, a mirror device for reflecting illumination emitted from the light generator thereby changing a path of the illumination, in which a reflection angle of the illumination can be adjusted, and a projection apparatus for enlarging and projecting the image produced in the image producer on the screen by reflecting the image to an incident illumination from the mirror device, wherein the path of the illumination is aligned to correspond to the whole image produced in the image producer to be projected on the screen by adjusting the mirror device.