Imran Khan, 34, of Pendle Street in Accrington, Lancashire, admitted taking the girl from Nairne Street in Burnley on 26 March.
He also admitted intending to commit a sexual offence and breaching a sexual offences' prevention order.
Following the hearing at Preston Crown Court, Khan was remanded in custody and is due to be sentenced on 23 October.
Police said the girl was bundled into the boot of Khan's car before being driven to Scarth Lane in Hapton where he exposed himself and tried to force her to commit a sexual act.
Khan then dumped her in a wheelie bin before she later freed herself and was found wandering alone in distress by other children, the court heard.
Det Insp Jim Elston of Lancashire Police said it was a "horrendous" and "terrifying offence".
Khan was convicted in 2008 of a sexual offence involving a 12-year-old girl, police said.
Mr Elston said: "While we have rigorous systems in place to manage sex offenders who have served a sentence and been released into the community, this cannot happen 24 hours a day and unfortunately on occasion an offender may go on to commit a further offence as happened in this case.
"There is currently a review ongoing into this particular case and we will clearly look carefully at the results of that to see if there are any lessons we can learn."
A registered sex offender has pleaded guilty to abducting a six-year-old girl who was taken in a car from the street.