Massage machine core and neck massage instrument

The utility model discloses a massage machine core which comprises a shell, a driving device is fixed in the shell, a driving shaft of the driving device drives an eccentric block movably arranged on the shell to rotate through a speed reduction device, an eccentric shaft is obliquely arranged on the eccentric block, and the eccentric shaft rotates in a frustum shape when the eccentric block rotates. An eccentric sleeve is rotationally arranged outside the eccentric shaft in a sleeving mode, a massage head is fixed to the upper end of the eccentric sleeve, the middle of the eccentric sleeve extends outwards to be provided with a limiting column, a limiting groove is formed in the shell, and the limiting column is limited in the limiting groove to move, so that the massage head swings front, back, left and right; the massage head is hollow, and a heating module is arranged in the massage head. The utility model further discloses a neck massage instrument provided with the massage machine core. The utility mode