A projection system, comprising a first light source which is an array light source, the first light source being divided into a plurality of illumination areas, and each illumination area may be independently controllable so as to generate a first illumination light field of which the brightness and darkness may be modulated; a second light source comprises an illumination unit and a light steering unit; the light steering unit redistributes illumination light emitted from the illumination unit to generate a second illumination light field of which the brightness and darkness may be modulated, wherein the first and second illumination light fields overlap to generate a combined light field. Also provided is a projection display method. The goal of simultaneously increasing image peak value brightness and lowering image dark field brightness is achieved, and a projection system that has a high contrast ratio is thus obtained.