A telescopic pen comprises a pen holder, a pen cap and a small fan, wherein the small fan is arranged on the top of the pen holder, a pull cord switch is arranged on the small fan; a pen tip is arranged on the end of the pen holder, a rubber ring is arranged on the bottom of the pen holder, a note door is arranged on the middle end of the pen holder, a groove is arranged below the eraser ring, a telescopic rod is arranged on the upper end of the pen holder, a mini calculator is arranged on the telescopic rod; the pen cap is arranged on the lower end of the pen holder, essence is arranged in the pen cap; the small fan is arranged on the top of the pen holder, and especially in the hot and muggy days, working and studying will be affected due to the hot and muggy days, the fan can be started through the pull cord switch, so as to cool and ease the anxiety and furthermore increase the work efficiency; the note door is arranged on the middle end of the pen holder, notes can be placed inside after the note door is opened, and when in need, the note door can be opened and thus some trifles can be conveniently recorded in the real time and it is not necessary to specially prepare notes, so as to provide convenience for work and study.