The 34-year-old Launceston man was found guilty by a Supreme Court jury of vaginally and anally raping his former partner in Summerhill on June 15, 2019.

Justice Michael Brett said the man was unreasonably jealous about the woman's new relationship.

"You were unhappy because you still regarded her as belonging to you," he said.

He said the man had demonstrated no remorse and his counsel Evan Hughes said that he maintained his innocence.

"The jury obviously accepted the complainant as a truthful and accurate witness. I am also of that opinion," Justice Brett said.

The court heard that the drug-affected, homeless man breached family violence orders when he turned up at the woman's unit.

When he was asked to leave he became abusive and called her a slut and an unfit mother.

He grabbed her in a bear hug and pushed her onto a bed and raped her causing a laceration in her anus.

He told police later that he had consensual intercourse, but his penis slipped and went into the wrong hole.

Justice Brett said he accepted the woman's evidence that she felt two thrusts.

"I have no doubt that it caused enormous pain," he said.

"You said she needed to be taught a lesson and the act of rape was used to punish her.

"You intended to degrade her... and wanted to use the act to hurt her."

Crown prosecutor John Ransom read a victim impact statement to the court in which the woman said that the rape was more horrifying because it was inflicted by a man who she used to love and had children with.

"It made me feel that no matter what I do or say he would never let me go," she wrote.

She said the rape made her panic around males because she was fearful of what they may do.

He set a non-parole period of three years and nine months and ordered that he be placed on the sex offender register for ten years after release.

In mitigation, Mr Hughes said his client had suffered retribution in jail for giving evidence in a murder trial in 2018.