Pen with illumination function

The invention discloses a pen with an illumination function. The pen is characterized by comprising a pen rod and a pen core, wherein cavities are formed in the tail portion of the pen rod; a folding supporting rod is arranged on the outer wall of the tail portion of the pen rod; the folding supporting rod is a two-section type flat plastic piece; an illumination light is arranged on the top of one end of the folding supporting rod; the other end, corresponding to the illumination light, of the folding supporting rod is connected with the pen rod through a folding shaft; power sources are arranged in the cavities; a control switch is arranged at the tail end of the pen rod; and the power sources, the illumination light and the control switch are electrically connected in sequence. By using the pen with the illumination function, the folding supporting rod can be expanded when the light is insufficient, and the illumination light on the top of the tail end of the folding supporting rod is utilized to illuminat