Police manning the checkpoint in Tambon Na Kaew in Koh Kha district pulled the truck over at 12.30am.
They decided driver Arthit Laorat, 32, from Khon Kaen, seemed nervous, so they searched the back of the truck.
They claimed they found 50 bags containing the meth.
Police say Arthit confessed to being paid to haul the drugs from Lampang to Pathum Thani’s Klong Luang district.
The investigation continues.