Florence had 24 hours earlier become the first Briton to triumph at a World Championships in the C1, and he and Hounslow went one better than their London 2012 silver medal in the C2 final, producing a time of 114.10 seconds for glory in Prague.
Czech pair Jaroslav Volf and Ondrej Stepaneck were just 0.04secs behind. Ladislav and Peter Skantar of Slovakia finished third.
“To come to the World Championships and win both races is just amazing, something I thought would never be done by anyone,” said Florence. “I was pretty happy with yesterday, but for it all to go so well two days in a row and get on top of the podium again today is unbelievable.
“It’s just gone so well the last couple of days and obviously a massive thanks to Rich as well. I’m very pleased for him to have joined me only 24 hours later as the world champion.”
Florence, who also won silver in the C1 at the Beijing Olympics, and Hounslow finished runner-up to compatriots Timothy Baillie and Etienne Stott at London last year.
“It was amazing watching David win yesterday and to be able to call myself a world champion is what matters. I’m really proud of what we have both achieved,” added Hounslow.
Florence finished his Canoe Slalom World Championships campaign in the Czech Republic later yesterday with a bronze medal in the C2 team event.