An angle-of-view testing method for a projection display device, including setting a reference viewpoint at a same side as a reflective surface associated with the projection display device, setting a metrical marker plate with a metrical marker at another side opposite to the reflective surface at a first distance from the reference viewpoint, projecting a testing picture onto the reflective surface by the projection display device, where light of the testing picture is reflected by the reflective surface toward the reference viewpoint, such that a projected image as a virtual image of the testing picture is observed at the reference viewpoint as being projected onto the metrical marker plate, determining the coverage of the projected image with respect to the metrical marker of the metrical marker plate, and determining an angle of view of the projection display device based on the determined coverage.