The pair - reigning Olympic, European and Commonwealth champions - had led the contest from the fourth round in Wuhan and held an eight-point advantage over home favourites Cao Yuan and Xie Siyi heading into the final round.
A straight shootout ensued as both pairings had the same final jump in their routine - the forward 4-1/2 somersault. Laugher and Mears were up first but could only manage an underwhelming score of 70.68, their worst mark outside of the required dives, for a total of 440.64.
Cao and Xie made no mistake when they took to the boards, wrapping up gold with a score of 88.92 for a winning total of 448.74.
Experienced Mexican partners Rommel Pacheco and Jahir Ocampo took the final spot on the podium with a total of 435.72, including a stunning score of 94.62 for their own take on the forward 4-1/2 in the final round.
Final leaderboard in full:
1. Cao Yuan, Xie Siyi (CHN) - 448.74
2. Jack Laugher, Chris Mears (GBR) - 440.64
3. Rommel Pacheco, Jahir Ocampo (MEX) - 435.72
4. Philippe Gagne, Francois Imbeau-Dulac (CAN) - 410.67
5. Mike Hixon, Sam Dorman (USA) - 392.82
6. Oleg Kolodiy, Oleksandr Gorshkovozov (UKR) - 386.52
7. Matthew Carter, Domonic Bedggood (AUS) - 386.01
8. Nikita Shleikher, Ilia Molchanov (RUS) - 384.48
9. Sho Sakai, Ken Tarauchi (JPN) - 384.24
10. Ahmad Azman, Tze Liang Ooi (MAS) - 379.41
11. Patrick Hausding, Lars Rudiger (GER) - 373.32
12. Giovanni Tocci, Andrea Chiaribini (ITA) - 347.82