Michael Allen scored two tries as Ulster eased to a bonus-point win in the Pro12 clash at Ravenhill.
Jared Payne set up tries for Luke Marshall and Allen as Ulster moved into a 15-3 lead at half-time.
Tries from Tommy Bowe and Rory Best, in their first game back after Lions duty, stretched the gap before Robert Barberi went over for a deserved Treviso try.
Allen completed his double as Ulster made it back-to-back wins after losing their opening two league matches.
The hosts made a blistering start and went over twice in the opening five minutes, only for the TMO to rule out tries both times.
Allen's foot went into touch as he sprinted over in the corner before a mass of bodies obscured the ball after a driving maul.
Paddy Jackson slotted over a penalty after 10 minutes but the the Italians hit back with a Mat Berquist three-pointer.
Ulster moved ahead on 18 minutes as Luke Marshall charged over from Payne's burst and lay-off, and this time the TMO gave the try after deciding there was no forward pass.
Jackson added the extras but he failed to convert following Ulster's second try in the 29th minute.
Payne was again involved, his pass out wide giving Allen an easy run-in to the line and ensuring a 12-point lead at the break.
Treviso enjoyed their first period of pressure on the restart and Alberto Di Bernardo fired over a penalty.
There was a touch of fortune with Bowe's try after 52 minutes, the Lions wing touching down after Ludovico Nitoglia failed to hold a cross-field kick from Jackson.
Jackson failed with the conversion and was off-target again after Best collected Dan Tuohy's pass before going over to secure the bonus point on 63 minutes.
Replacement lock Lewis Stevenson was sin-binned two minutes later, paying the price for a series of Ulster infringements.
Treviso finally broke through the Ulster defence with 10 minutes left, replacement Barbieri squeezing over and Di Bernardo converting.
Allen rounded off an impressive display with a run to the corner in the final minute before Jackson converted with the last action of the game.
Ulster coach Mark Anscombe said he was "pretty happy" with his team's performance.
"To score five tries is always rewarding and also to get the bonus point," he added.
"We played some really good rugby in the first half, which was pleasing.
"We lost a bit of energy in the forwards pack in the second half, but we are heading in the right direction."
Ulster: Gilroy, Bowe, Payne, L. Marshall, Allen, Jackson, P. Marshall, Court, Best, Lutton, Henderson, Tuohy, Diack, Henry, Wilson.
Replacements: McKinney for Gilroy (80), Cave for Payne (62), Heaney for P. Marshall (67), Black for Court (68), Herring for Best (72), Ross for Lutton (77), Stevenson for Henderson (48), Williams for Wilson (62).
Sin Bin: Stevenson (66)
Benetton Treviso: McLean, Nitoglia, Campagnaro, Sgarbi, Loamanu, Berquist, Gori, Rizzo, Ceccato, De Marchi, Pavanello, Fuser, Favaro, Zanni, Vosawai.
Replacements: Semenzato for McLean (48), Di Bernardo for Berquist (31), Fernandez-Rouyet for Rizzo (38), Budd for Fuser (43), Barbieri for Vosawai (31). Not Used: Maistri, Di Santo, Bernabo.
Ref: Ian Davies (WRFU).