Greens leader Richard Di Natale has defended his decision to dump Sarah Hanson-Young from her immigration portfolio, but promised the party's strong pro-refugee stance would not change.

Senator Hanson-Young said she was "disappointed" about being transferred to the education, finance and trade portfolios in a reshuffle announced on Thursday, revealing she had "fought hard" to retain responsibility for asylum seekers and immigration.

Senator Di Natale praised his colleague for being "a tremendous advocate" for refugees in the high-profile role she held for nine years, but said it was time for a refresh.

"I think the country owes her a great debt," he told the ABC. "She's led the charge on a more humane, compassionate and decent approach to the treatment of refugees."