The incident took place near the Mauli railway crossing on the Phagwara-Goraya section last night, GRP Post In-charge Gurbhej Singh said.
The deceased was identified as Pala Ram, a resident of Takhran village, he said, adding that the man jumped before the Jaipur-Amritsar Express.
The reason behind him taking the extreme step is not known, he said.
The body was handed over to his family after post mortem at the local Civil hospital today, the GRP official said.
A case under Section 174 of the CrPC was also registered, he said.