The invention discloses a luminescent device including the base plate, many light sources and the lens part. The light sources are arrayed on the base plate which is covered by the lens part. The lens part has a saddle type refracting surface on the top of the light source which has a saddle region and two ridge regions. The saddle region is between the ridge region and the light intensity of the ridge is bigger than the saddle region. In otherwise, the invention also discloses a surface light source module which can provide the good-uniformity surface light source. The light ray can be emit from the saddle type refracting surface directly, so it can't loss the energy and improves the luminous efficiency to increase the brightness of the surface light source. |