Attorneys for Mitchell argue that he is mentally ill, but Smart testified otherwise Tuesday. She told jurors that Mitchell had planned another abduction and that he wanted to take her cousin, Olivia Wright, as his third wife.
Smart watched him pack his bag with the same ropes and knife he had used to kidnap her.
"He said that he was going to try the same way he kidnapped me, and then he would take her back up into the canyon," Smart said.
The attempt was unsuccessful because Mitchell made too much noise while climbing through a window at Wright's home. Another kidnap attempt in San Diego also failed.
Smart explained how Mitchell raped her repeatedly and forced her to drink alcohol and smoke marijuana.
Smart said Mitchell took her on several trips into Salt Lake City, including a trip to a rave party. On one occasion, they visited the library, and Smart said it was the closest she got to being rescued.
A police officer asked her to remove her veil, but Mitchell said their religion forbade the officer from doing so. The officer pressed harder, but eventually gave up.
"I was mad at myself, that I didn't say anything," Smart said. "I felt terrible that the detective hadn't pushed harder and had just walked away."
She said Mitchell said it was a sign they needed to go to San Diego.
There, he forced her to look at a Hustler magazine while drinking. Smart said she threw up, so Mitchell forced her to lie in her own vomit.
While in California, he showed her a newspaper photograph of her parents. As she looked at it, Smart said Mitchell asked her if she was surprised they had not given up hope of finding her.
Smart told the jury on Monday that she awoke when she felt a cold knife on her neck and a man threatening to kill her and her family if she didn't go with him.
She was found nine months later when motorists spotted her walking in a Salt Lake City suburb with Mitchell.
Mitchell's attorneys are expected to cross examine Smart on Wednesday.
If convicted, Mitchell could spend the rest of his life in prison.
The Associated Press Contributed to this report.