The boy was filming trains with his father when abuse was hurled at him, said British Transport Police.
PC Emma Williamson said: “The boy was with his father at the station filming and taking photos of trains passing through when he was approached by a man.
“The man walked across the tracks from platform 2 towards the victim, who was stood next to the level crossing barrier which was down at the time, then swore at the boy and verbally abused him.
“He then trespassed back across the tracks and walked up onto platform 1 and out of sight.
“This must have been a very upsetting experience for the young boy who was simply on a day out with his dad enjoying his hobby.
“The man’s actions could also have had fatal consequences. Trespassing on the tracks and misusing level crossings in this way is extremely dangerous, he was very lucky a train wasn’t coming or the outcome would have been unthinkable.
“We have managed to isolate a CCTV image of a man we believe will have information about the incident – who is he? If you know him please contact us.”
Anyone with information about the incident at 6.45pm on Friday, March 25 should call British Transport Police on 0800 40 50 40.