The American twins will be going for their fourth title at the season-ender on Sunday against Brazil's Marcelo Melo and Croatia's Ivan Dodig, although they have not triumphed since 2009 when the event first switched to London.
Melo and Dodig beat Lukasz Kubot and Robert Lindstedt in a deciding set match tiebreak.
The Bryans dropped only seven points in a one-sided opening set, an unusual occurrence this week when the doubles matches have been fiercely contested, but they had to work a bit harder in the second set against the fourth seeds.
ATP World Tour Finals
Bryans claim fourth Tour Finals title
16/11/2014 AT 19:06
The 16-times grand slam champions have already guaranteed the year-end top ranking for the 10th time in the last 12 years and will cap another great year with victory on Sunday.
ATP World Tour Finals
Federer reaches London final with comeback win over Wawrinka
15/11/2014 AT 23:01
ATP World Tour Finals
Tetchy Djokovic blames exhaustion for Nishikori scare
15/11/2014 AT 19:07