Pen and electronic device

The invention discloses a pen and an electronic device. The pen comprises a pen point, a pen tail, a pen holder sleeve and a radial driving assembly; the pen holder sleeve is defined by at least two pen holder sleeve pieces which are distributed in the circumferential direction, the two ends of the pen holder sleeve pieces are in radial moving connection with the pen point and the pen tail, the radial driving assembly is in drive connection with the pen holder sleeve pieces and used for driving the pen holder sleeve pieces to be expanded outwards along the radial direction of the pen holder sleeve, when the pen is normally used, through the radial driving assembly, the pen holder sleeve pieces are expanded outwards in the radial direction of the pen holder sleeve, the outer diameter of the pen holder sleeve is increased, comfort holding is facilitated, user experience is improved, when the pen is not used, the pen holder sleeve pieces shrink inwards in the radial direction of the penholder sleeve, the outer diameter of the pen holder sleeve is reduced, the whole pen becomes fine and small, and space occupying is reduced.