Paris Hilton Injures Knee on Music Video Set After Recent Trailer Fire

Paris Hilton is putting blood, sweat and tears into her new music video ... catching a bloody knee injury on set after her recent catastrophic trailer fire.

The heiress gave a glimpse into her latest challenge shooting the "Bad Bitch Academy" music video ... which included a cut to her knee that required medical attention ... before filming could resume.

Watch the vid ... Paris is seen taking a closer look at her blood-covered knee, asking those on set if there's glass inside the wound -- the foreign object turns out to be a rogue sequin ... likely detached from her shimmery silver outfit on the shoot.

Crewmembers encourage Paris to power through the injury, calling her a "trooper" ... noting they'll cover up the cut with makeup, and it won't be visible in the next shot.

The show must go on ... and the socialite agrees, declaring she's put her all into this music video.

Paris is, of course, referring to her makeup trailer fire in mid-August ... which destroyed a number of her designer clothes -- including custom Swarovski outfits -- purses, jewelry, computers and personal mementos.

TMZ broke the story ... Paris was in downtown Los Angeles shooting her new music video when her trailer went up in flames -- though, thankfully no one was injured.

No word yet on what caused the blaze ... but we're told the L.A. Fire Department is investigating.