Putrea Ngan, 20, died in hospital, following the accident on the Si Khiew-Ubon Ratchathani road at 9.30pm.
He had been the passenger on a motorcycle ridden by Komcharn Duangkrachai, 21, who was severely injured in the accident, police said.
When rescuers arrived at the scene, Putrea, who had lost both legs in the crash, was barely breathing.
He later died at Surin Hospital.
The motorcycle had exited from a village road into the main road at a fast speed, crashing into the left side of a trailer truck, which was driven by Boonyarit Anuthool, 27, police said.