The train has been fitted out with a library car by Norwegian train company NSB, and anyone with a library card will be able to withdraw books.
"I wanted to make this journey not only to share my love of reading with others, but also so that others will have a chance to share their love of reading with me and others," she said as she launched her journey in the town of Bodø.
The train stopped at Fauske, Rognan, and Mo i Rana on the first day, and will travel south to Snåsa, Steinkjer and Stjørdal on Wednesday.
At each stop the Crown Princess, who had the idea for the tour, will host a literary event.
"I wanted to convey my great love of reading. I also love trains," she tweeted on the first day. "On the train we travel slowly. As we do in books."