David Cotterill and Ashley Williams found the net either side of half-time as the Swans completely outplayed their visitors.
There was no place in the Swans squad for Angel Rangel, while Gorka Pintado continued up front, leaving Shefki Kuqi on the bench.
Swansea went close in the 15th minute when Darren Pratley crossed to Pintado but his header glanced wide of the post when he was well placed.
Midway through the half Darren Pratley and Nathan Dyer combined to send the ball drifting across the danger area, but no-one was on hand to turn it into the net.
In the 28th minute there were shouts for a penalty when Dyer went down in the area following a challenge by Sean St Ledger and Andy Lonergan. The Preston keeper resumed after lengthy treatment to a facial injury.
The Swans took the lead in the 35th minute when Cotterill was brought down by Youl Mawene on the edge of the area. Cotterill took the free-kick himself and curled the ball over the wall and into the far corner with Lonergan hopeless.
No changes were made for the second half that began with Dyer streaking threw the Preston defence, only to send his right-foot shot spinning beyond the far post.
Three minutes after the break the Swans doubled their lead when Williams rose highest to head a Cotterill free-kick into the back of the net.
Joe Allen sent Lonergan sprawling to his right to push away a 25-yard drive as the home side kept up the pressure and in the 78th minute Cotterill rifled a shot against the post with the keeper beaten.
All three substitutes were used by the Swans but they couldn't add to their tally, although it was a very convincing victory.