Welshpool headteacher Eirios Hall has been found guilty of seven counts of unacceptable professional conduct after a four-day hearing.
In the longest-running tribunal of its kind in Wales, the professional conduct committee panel said that seven of the 14 allegations against her showed that she had fallen below the standard expected of a registered teacher.
Hall, 59, had been accused of bullying and physically manhandling pupils at Ardwyn Nursery and Infants School.
Amongst the charges upheld by the tribunal were that she did pull a four-year-old pupil aggressively by his jumper; she did drag and shake other pupils, and she was both aggressive and humiliating in telling a child with a speech impediment to 'speak properly'.
Four allegations were partly proven - for example, when dealing with a boy who'd bitten another child, she was found to have pretended to bite the boy's arm, saying "How would you like to be bitten?"
But although it was found that she did pin down a boy with severe behavioural problems, the panel decided this was the right course of action as he was in danger of hurting himself or others.
She was also found not to have mocked a boy whose father had died.
She has been suspended from teaching from teaching for one year after the panel took into account her long career and previously unblemished record.
Hall had denied all the allegations against her at the General Teaching Council for Wales hearing, held in Cardiff.
She claimed she told the boy with a speech impediment to 'open his mouth and speak properly' as part of his speech therapy, and that she had pulled a child up by his sweatshirt because she thought he was going to fall down.
In mitigation, the tribunal heard that her life has already been ruined; that she has already lost her job and had to move house.