Guy, 19, from Bury, added the 200m freestyle title to Monday's 400m gold, beating Serbia's Velimir Stjepanovic to win in one minute 47.06 seconds.
Jazz Carlin clocked 4:07.42 to win silver in the 400m freestyle, matching her runner-up finish in the 800m.
Ross Murdoch, Luke Greenbank, Stephen Milne and Liam Tancock all won bronze.
Greenbank, who won two individual golds and two relay silvers at this year's European Games in Baku, recorded 1:58.83 in the 200m backstroke, one second behind silver medallist Masaki Kanek of Japan.
Milne and Tancock rounded off the action at the Hamad Aquatic Centre in the 1500 freestyle and 50m backstroke respectively.
South Africa's Cameron Van der Burgh remains unbeaten in the 2015 World Cup Series across both the 50m and 100m breaststroke events, winning the 100m in a time of 59.68.
The 27-year-old was the only finalist to dip beneath the one minute mark, Murdoch recording 1:00.84, just behind Hungarian Daniel Gyurta (1:00.60).
Teenager James Guy claimed a second gold as Great Britain increased their medal tally to nine after two days of the Swimming World Cup in Doha.