A B-double truck driver is being treated for shock after he ran over a man who was lying on a NSW highway, police say.

A man has died after being run over by a B-double truck on a NSW highway.

Police say the truck driver is being treated for shock after he hit the man who was lying on the Newell Highway near Dubbo just after 2am on Sunday.

The driver called emergency services shortly after, saying he had run over a man in the middle of the southbound lane.

Police say the man sustained multiple injuries and died at the scene.

He has not been identified as yet.

The 46-year-old Queensland truck driver was treated at the scene for shock before being taken to Dubbo Base Hospital for mandatory blood and urine tests.

Police say the section of the highway where the incident occurred does not have street lighting.