A spindle mechanism of a winding machine includes a spindle box provided with a mounting hole; bearings respectively arranged at both ends of the mounting hole of the spindle box to form a front bearing and a rear bearing, the bearing comprises an inner ring and an outer ring; and a spindle, the spindle is arranged to pass through the mounting hole of the spindle box and is rotatably positioned on the spindle box by means of the bearings, and the number of the front bearings is the same as the number of the rear bearings, and the outer ring of at least one of the front bearing and the rear bearing is not restricted in an axial direction so as to form a free end.