The present application relates to a linear light source using ultraviolet light emitting diodes (LEDs), and a photopolymer 3D printer comprising the linear light source. The linear light source may include a substrate distanced from a polymer case of the photopolymer 3D printer and an ultraviolet LED array in which a plurality of ultraviolet LEDs, which project ultraviolet rays toward the polymer case, are arranged on the substrate in multiple rows in the X-axis direction. The arrangement of the multiple columns in the Y-axis direction is at an oblique angle to the multiple rows.