The attacker, identified as Abhijit Das in Indian media, entered the building on Monday in the state of west Bengal.
Das told cops he had decapitated his wife Amba – but they refused to believe them.
He then reportedly produced her head from a bag and was locked inside the station.
A team of cops raided his house in the village of Lakshmi Janardhanpur.
They discovered Amba’s beheaded body in a pool of blood, The Times of India reports.
It has since been sent for a post-mortem examination.
“He suspected that Amba was having an illicit relationship with a neighbour”
Police spokesman Tathagata Basu
Police spokesman Tathagata Basu said: “We have interrogated him and he confessed to have killed her.
“He suspected that Amba was having an illicit relationship with a neighbour. He had a fight with his wife on Sunday night.”
Das has been charged with murder and is due in court.
Earlier this month, another man in the US was arrested after allegedly cutting his dead mum’s head off with a hacksaw.
Police have held Isaac Warriner in Texas on charges of abusing a corpse and tampering with evidence.
The 22-year-old has not been charged with killing his mum, Sarah Warriner, 65.