DJ Khaled hosted a summer cruise music festival a couple years ago -- and now he's back with another one that'll feature Cardi B and Post Malone ... TMZ has learned.

Production sources tell us, DJK has teamed up with Cardi and Post to headline the summer cruise, which goes from Miami to the Bahamas and back again. The ship heads out on June 28, and returns on July 1 ... plenty of time for onboard debauchery.

Khaled teased the announcement on social media, which he'll officially make Friday afternoon.

Just a reminder ... Khaled hosted this same cruise fest back in 2017 with Future, Lil Wayne and A$AP Rocky -- calling it Summerfest Cruise at the time. They passed on back-to-back years, but apparently ... the demand is there to run it again in 2019.

No word on ticket prices, but if a 4-day voyage at sea with Cardi and Post performing throughout sounds good ... the extra perks will win you over completely.

In addition to the shows, guests will have opportunities for meet and greets with performers, parties with the stars and even a discussion panel. There's also your standard cruise entertainment -- comedy shows, pool parties, casino games, nighttime events ... and a 24-hour buffet.