The police said Sittha Amornratnamniueng was immovable when he fell from the train's ladder on to the track at the station in Muang district once the train arrived at 8:30am.
Sittha was heading to the Fine Arts College in Bangkok's Lat Krabang district.
The student is 180cm tall and weighs about 140kg. He appeared to have back injuries and could not move. Rescuers took him to the Buddha Sothorn Hospital.