A jury found Matthew Haylett, of Witton Road, Birmingham, guilty of possessing a disguised firearm, possessing Class B drugs and a racially aggravated public order offence.
On Friday he returned to Wolverhampton Crown Court and a judge sentenced him to five years’ imprisonment.
At just before 7pm on April 20, 2019, a member of rail staff was walking through Wolverhampton railway station when he noticed Haylett arguing with two young men.
He overheard Haylett say: "I’m going to cut you up" before reporting what he saw to British Transport Officers at the station.
The officers searched Haylett and discovered a torch in his pocket with “police” printed on one side and “80,000w” on the other, as well as a small black plastic bag containing four grams of cannabis.
Officers quickly realised the torch was in fact a taser.
After being arrested the 44-year-old released a volley of abuse at the officers using racist and homophobic slurs including the term "dirty stinking white dirty dog".
Haylett later claimed he found the item on a bus and was not aware it was a taser.
Detective Inspector Shani Plumb, investigating officer in the case, said: "How this device came into Haylett’s possession remains a mystery.
"However, there are no question marks over how despicable his behaviour was on that day. No emergency worker should be subjected to a torrent of abuse for simply doing their job."
He added: "I am grateful to the member of rail staff who reported Haylett to our officers – his action has resulted in the seizure of a dangerous device and a hostile offender behind bars.
"Anyone who witnesses suspicious behaviour on the railway should always report it to us. You can do so by speaking to our patrolling officers, texting 61016, or calling 0800 40 50 40."
Detective Plumb warned anyone who plans to commit crime on the rail network they will be brought to justice.
He said: "We will always take action to ensure the UK rail network remains a safe environment for passengers."