Martin Bryan, a 33-year-old farming student at Harper Adams University, in Newport, also told the conductor "I'll f*****g kill you, do you want to die?"
The victim said he had never faced such aggression.
Telford Magistrates Court heard that on a Shrewsbury to Wellington train at around 11.30pm on April 14 this year, the conductor encountered Bryan on a train, who was with another man and carrying a bottle of wine. About 45 minutes later, Bryan's demeanour "appeared to change".
"He became manic in his behaviour and was abusive," said Sara Beddows, prosecuting.
Bryan, of Valiant Road, Cosford, Albrighton, who also works part time in the cafe at Attingham Park, was looking for the phone of his partner, who was also on the train. He was confronting passengers aggressively as he tried to find the device.
When the conductor approached him, Bryan told him to "f*** off", before saying to some unknown men "I'll smash your faces in" and "I'll f*****g kill you".
Bryan got off the train at Wellington station, as did the conductor. That was when Bryan threatened violence against him. The conductor had to put his hand out to keep Bryan away. The police were called and Bryan was arrested.
In a victim impact statement read out in court, the conductor said: "In my role, I come across all sorts of situations. I can usually diffuse it by giving respect and being calm.
"This was the worst experience I have ever dealt with in 14 years."
He added: I don't enjoy my role like I used to. I feel vulnerable a lot of the time.
"I was so intimidated. It brings back bad memories. I used to do as much overtime as I was legally allowed. Now I don't do any."
Bryan pleaded guilty to using threatening behaviour to cause fear of unlawful violence. He has one previous conviction for drink driving.
Bryan's legal advocate said his client was "embarrassed by his behaviour" and it was "totally out of character".
Magistrates handed Bryan an 18-month conditional discharge and ordered him to pay £250 in compensation. He was also ordered to pay £135 in court costs and a £22 victim surcharge.