A tiled head-mounted display device, comprising: an optical component including a plurality of prisms with free-form surfaces, each prism being a wedge prism comprising a first optical surface, a second optical surface and a third optical surface; and a display component including a plurality of micro-displays, wherein the number of the micro-displays and the number of the prisms with free-form surfaces is identical. The tiled head-mounted display device according to the present invention is compact and light, provides wide field of view and high resolution, especially for the optical tiling head-mounted display device, the exit pupil planes of each display channels are coincident, thus avoiding pupil aberration and keeping exit pupil diameter and eye clearance same as the single ocular. There is no resolution variance throughout the entire field of view, thus preventing extra trapezoid distortion. The tiled head-mounted display device according to the present invention can be readily applicable to augmented environments applications by simply adding an auxiliary free-form lens behind the free-form prism.