The invention relates to a pole piece ash brushing mechanism good in symmetry. A motor, a first gear shaft, a first gear, a second gear shaft, a second gear, a third gear shaft, a third gear, a fourthgear shaft, a fourth gear, a supporting plate, a left ash brushing box, a right ash brushing box, a left brush wheel, a right brush wheel, a left connecting block, a right connecting block, sliding blocks, guiding rods, an adjusting plate, a left sliding plate, a right sliding plate, an air cylinder, an air cylinder connecting head and sliding rails. The pole piece ash brushing mechanism is reasonable in integral structure design, when the air cylinder drives the left sliding plate and the right sliding plate to move towards the left-right outer sides or inner sides along the sliding rails, the corresponding sliding blocks move downwards or upwards along the guiding rods, it is guaranteed that the moving distances of a left brush wheel system and a right brush wheel system are equal and are constantly symmetric relative to the axis center lines of the two brush wheels, the ash brushing quality is improved, the structure is firm, and the ash brushing speed is high; and in addition, a pull handle mechanism is additionally arranged so that brush wheel replacement can be convenient, detachment of the whole mechanism is not needed, manpower and time are saved, and practicability is high.