A device for projecting a test pattern for evaluating the image-capturing properties of a lens module includes a light emitting assembly. The light emitting assembly includes a light emitter and a patterning plate on the light emitter. The patterning plate includes a first surface facing the light emitter and a second surface opposite to the first surface. The second surface is concave and defines a patterning groove. The light from the light emitter passes through the patterning groove to form an original pattern for testing, the display of a test pattern being instantly selectable and displayable.