David Sosa Salomon stabbed his mother several times in February last year.
He was convicted after a trial in December after a trial at Bristol Crown Court and was sentenced on Friday 9 February.
Jurors were told during the trial the public intervened to help the woman when she was attacked by Salomon.
The 37-year-old drove from his temporary caravan home in Oldmixon Crescent, Weston-super-Mare on Tuesday 28 February 2023 to Filton.
He waited near a pub in Filton Avenue that afternoon until the bus his mother regularly boarded stopped. When she alighted from the bus, Salomon used a knife to attack her.
Members of the public intervened to help protect the victim and to get Salomon to drop the knife. They called the police and officers arrested Salomon at the scene.
He admitted wounding with intent to cause grievous bodily harm, but was convicted by a jury of attempted murder at the end of last year.
The victim thanked members of the public who came to her aid and their efforts were also praised by the judge.
Sosa Salomon, was given a 19 year sentence.
