Steve Tandy’s men ran in seven tries in the Liberty Stadium rout, which saw them leapfrog the Scarlets into fourth in the league table.
Kahn Fotuali’i, Tom Habberfield and Ashley Beck all touched down in the opening quarter and Tom Isaacs secured the bonus-point early in the second-half.
The Dragons gave themselves a glimmer of hope with a Dan Evans try but Dan Biggar put the result beyond doubt.
Toby Faletau snatched a late consolation but the hosts had the final word with further tries from Dmitri Arhip and Justin Tipuric.
The Ospreys, fully loaded with six of their Six Nations stars, came out firing at the Liberty Stadium.
They launched a relentless barrage of attacks and Fotuali’i eventually sniped over from a close-range quick-tap.
Biggar knocked over the simple conversion and the hosts continued their early onslaught. They once again surged up field and following a sustained period of pressure Jonathan Spratt displayed sublime sleight of hand to send Habberfield into the corner.
Biggar converted from the touchline to hand the Ospreys a 14-point lead after little more than seven minutes.
Steffan Jones responded with the Dragons first points but they were unable to build upon any momentum gained with the Ospreys claiming their third try.
This time Samoan scrum-half Fotuali’i was the provider and he sent Beck over on the switch.
Biggar was once again on the money and the Dragons woes were compounded with the loss of their captain, Lewis Evans.
That meant Faletau was brought on earlier than expected but he could do little to stop Biggar stretching the lead to 24-3.
Jones once again responded for the visitors and they withheld the Ospreys in the closing stages of the half as the scores remained 24-6.
It took the hosts just two minutes after the restart to wrap up the bonus-point, with Richard Fussell breaking clear and combining with Fotuali’i to send Isaacs clear.
Darren Edwards’ men rallied with Evans finishing in the corner but their revival was short-lived with Biggar claiming a converted try to stretch his tally to 18.
Faletau capitalised on loose ball at the back of an Ospreys scrum to race clear and steal a consolation try.
But the hosts continued to turn the screw with two late tries. First Arhip was rumbled over from a driving maul, then Tipuric collected a Jonathan Spratt cross-kick to complete the rout.
