He had already been dismissed by Sandy Lane Infants School, Caldicot, Monmouthshire, but denied the claims.
He did not attend the two-day Cardiff disciplinary hearing, but in a letter said he lacked support at the school.
A catalogue of alleged abuse involving Mr Warner's class of five and six-year-olds at the school was outlined.
He was said to have shut three children in a store cupboard, knocked another off a chair and dragged a boy by his jumper across the school hall.
Trainee teaching assistant Gemma McCluskey saw the pupil being held by the throat and ran sobbing from the classroom shouting: "He's throttling him," the panel heard.
Head teacher Susan Richards told the disciplinary panel they were "appalled" by what Miss McCluskey reported.
The incident happened after the boy jumped into his teacher's back and put his arm around his neck in a classroom prank.
Mrs Richards said: "I was concerned about the safety of the children and my priority was getting Mr Warner out of the classroom.
"In more than 30 years of teaching I had never dealt with such a severe case. He could not cope or control his temper.
The hearing was told of several incidents involving the teacher "Miss McCluskey said she could not believe a teacher could do such a thing and ran out."
Mr Warner was also accused of knocking the boy he had grabbed by the throat from a chair, banging his head on the tiled floor.
