The 'Mean' singer, who has had roles in Valentine's Day and The Lorax, revealed that she has read many scripts over the years but feels it would be "unfair" to take parts from other actors who may want them more.
In an interview with The Philippine Daily Enquirer, Swift explained: "I've been reading scripts for about five years - just kind of under the radar, asking my agents to please send me everything that might be good. In my free time I just read and read.
"When I look at acting careers that I really admire, I see that it's been a precise decision-making process for these people. They make decisions based on what they love and they do only the things that they are passionate about. They play only characters that they can't stop thinking about."
Swift continued: "If I got a script that I thought was okay and a character that I kind of liked and could pull off but wasn't obsessed with, that would be unfair to someone else who might be obsessed with that character. So if I do a movie, you will know I cannot think of anything other than that character.
"I'm such a fan of great writing and great storytelling. I'm looking for great, powerful writing behind whatever cast is surrounding it, whatever director is steering it - that would all be peripheral to the fact that the story is brilliant and has to be told."
Swift recently said that she is not uncomfortable being a role model and that she is always conscious of the effect she could be having on younger fans.
Watch a trailer for The Lorax below: