The man, named by state media as Ji Zhongxing, 34, from central Shandong province, was injured and taken to hospital.
No-one else was hurt in the blast, which filled part of the Terminal 3 arrivals hall with smoke.
An online microblog attributed to the man says the explosion was to protest at his ill-treatment by Chinese police.
The blog suggests his lower body was paralyzed after he was alleged to have been heavily beaten by security agents in southern China in 2005.
Mr Ji, who is alleged to have been operating an unlicensed motorbike taxi service, was also apparently dissatisfied with the way his complaints against the authorities had been dealt with.
State news agency Xinhua said he detonated the device - a package of gunpowder taken from fireworks - after being prevented from distributing leaflets.
Photos posted on China's Weibo microblogging site showed a dark-haired man waving a white package in the air before the explosion.
Later images from the airport showed the wheelchair on its side with officials treating him on the floor.
Smoke drifted through the terminal after the blast, which occurred shortly before 18:30 (10:30 GMT) near one of the arrival gates.
Xinhua showed several medical workers providing emergency treatment, with police officers also at the scene.
Officials say order has been restored at the airport and there is no disruption to flights.
A man in a wheelchair with an apparent grievance has detonated a small device at Beijing International Airport.