The present application provides a projection screen and a projection system. The projection screen includes an optical structure layer and a reflective layer, where the optical structure layer includes a plurality of microstructure units; each of the plurality of microstructure units include a first sidewall and second sidewalls; the reflective layer covers at least part of the first sidewall to form a first working surface, and the reflective layer covers at least part of the second sidewalls to form second working surfaces, respectively; the first working surface deflects an input image beam, and at least part of the input image beam is transmitted to viewer's field and the second working surfaces; and the second working surfaces deflect an input image beam came from the first working surface, and the input image beam came from the first working surface is transmitted to the viewer's field. The present application improves the brightness evenness of the projection screen.