a flexible vertical grinder , having a main shaft mounting frame on a grinder frame ; a main shaft is mounted on the main shaft mounting frame ; a stelliform bracket is mounted on the main shaft ; a hammer wheel grinder and a material - sorting balance wheel device are mounted on the stelliform bracket ; the material - sorting balance wheel and the hammer wheel are on the same horizontal plane . the vertical grinder can apply different grinding forces according to different specific surface areas of the to - be - ground material , and can grind materials of different grades properly but not excessively , thus greatly improving crushing efficiency , having good overall rigidity and stable operation , and facilitating maintenance .