A B-double carrying white wine from the Barossa was engulfed by flames on the Dukes Highway outside Cooke Plains.
Emergency services were called to the scene just before 6.45pm on Wednesday.
Five CFS fire crews, with approximately 25 firefighters, arrived to find the driver had safely exited the vehicle and detached the prime mover, as flames continued to engulf both trailers – causing around $400,000 worth of damage.
Firefighters were able to control the blaze in under an hour and remained on scene until the truck was removed to prevent reignition.
SA Police were also on scene, with traffic control put in place around the incident.
The CFS says the fire is believed to have been caused by a mechanical fault in one of the trailers.