An aquarium cultivation illuminating device, comprising a first light incident surface (A0) located above a light source, a second light incident surface (A1) surrounding the light source, a reflecting cone located above the first light incident surface (A0), a cylindrical light emergent surface (A4) surrounding the reflecting cone, and spherical light emergent surfaces (A5, A6) having variable curvatures and surrounding the second light incident surface (A1). The first light incident surface (A0) is in a spherical shape bulged toward the light source. The first light incident surface (A0) and the second light incident surface (A1) together form a cavity recessed upward from a bottom surface (A7) of a lens and used for receiving incident light of corresponding angles, and an annular prism group in a vertex shape is formed on the bottom surface (A7) around the center. The reflecting cone is recessed downward from a top surface (A8) of the lens to form a nearly conical surface (A2), the connecting line of an apex (A3) of the reflecting cone, the central point of the first light incident surface (A0) and the central point of the light source forms an axisymmetrical line of the lens, and the top surface (A8) of the lens is a smooth free-form curved surface or a frosted surface. The curvatures of the spherical light emergent surfaces (A5, A6) having variable curvatures gradually increase from top to bottom. The aquarium cultivation illuminating device has a large light emergent angle, forms a light spot having the natural light irradiation uniformity, and facilitates fish growth.L'invention se rapporte à un dispositif d'éclairage de culture en aquarium, qui comprend une première surface d'incidence de lumière (A0) se trouvant au-dessus d'une source de lumière, une seconde surface d'incidence de lumière (A1) entourant la source de lumière, un cône réfléchissant situé au-dessus de ladite première surface d'incidence de lumière (A0), une surface de sortie de lumière cylindr
