Pen case with illumination function

The utility model relates to a night writing pen, in particular to a pen case with an illumination function. The pen case comprises a pen container, and is characterized in that a light scattering head is arranged at the front end of the pen container; a refill in the pen container penetrates through a through hole in the center of the light scattering head; a battery, a small lamp and a switch are arranged at the rear part of the pen container; the small lamp is connected with the battery through a wire and the switch, and is connected with the light scattering head through a light guide pillar; the light scattering head is an organic glass body; the small lamp is a light-emitting diode; an ultraviolet bulb is arranged at the rear end of the pen container, and is connected with the switch and the battery. The night writing pen has the advantages that the night writing pen can be used for writing at night without the limitations of places and time, is an optimal writing tool for a camping site, and can further be used for providing illumination.