Angel di Maria opened the scoring for the visitors on the 16th-minute mark, successfully following up on Syam Ben Youssef's block of an effort from Serge Aurier to notch his fifth league goal for Les Parisiens since joining from Manchester United over the summer.
The keeper was unable to prevent the Swede from securing his side's second as the break approached, however, as he powerfully shot in from outside the penalty area for his 15th league goal of the campaign.
The result was put beyond doubt five minutes after the restart when Di Maria chipped in coolly from six yards out.
Caen could have found themselves a consolation with 10 minutes of normal time remaining when Thiago Silva was punished for pushing Andy Delort near the post. The striker stepped up himself for the spot kick but PSG keeper Kevin Trapp got down low and right to make the save.
The result means that Laurent Blanc's side are now unbeaten in Ligue 1 since March and enter the winter break with a record 51 points, some 19 clear of nearest challengers Monaco.
Caen, meanwhile, will end 2015 an impressive fourth place in the league.