The 60-year-old homeless man was sentenced to four years in prison recently by a local court for setting the bus ablaze.
The man surnamed Wang said he committed the crime as he wanted to return to prison to avail the facilities of food and accommodation, China Daily quoted Beijing Times as reporting.
Wang, who boarded a bus in Beijing's Fengtai district in August, last year, set fire to the driver's seat, causing panic among the passengers.
He reportedly confessed that life out of prison without a fixed residence or relative support made him miss his time in jail.