The Plymouth diver finished fourth overall in the 10m competition behind home favourites Huixia Liu and Ruolin Chen and Canada’s Meaghan Benfeisto.
Couch was the only Great Britain diver to reach a final on the last day of competition at the Water Cube, the venue for the 2008 Olympic Games.
Fellow Plymouth stars Sarah Barrow and Tom Daley missed out on progressing to the last six in tough semi-finals.
Barrow found herself in the same heat as Couch where she finished fourth with 334.30 points. Liu won the semi win 401.80 points, ahead of Couch with 354.00, with Malaysia’s Pandelela Rinong third with 349.15.
Daley was also fourth in his semi behind China’s world champion Qiu Bo, American’s Olympic champion David Boudia and Germany’s Sacha Klein with a disappointing score of 446.35.
The men’s final did throw up a surprise with Bo missing out on a medal by finishing fourth behind his team-mate Jian Yang, Boudia and Klein.
The women’s final was dominated by China’s Liu who won by 25 points. She scored 423.10, with Chen finishing with 398.90, Benfeisto 393.45 and Couch with 351.90.
Great Britain’s divers now move on to Dubai for the second leg of the series.