Chen Guanming, 57, said his goal had been to "spread the Olympic spirit" on his journey through war zones, floods, and extreme temperatures in countries including Taiwan, Turkey and Iraq.
"During this rickshaw journey, I've travelled through 16 countries, and a distance of more than 40,000 miles," Chen told AFP in London's central Soho district, a day before the Games begin.
"I wanted to arrive on time for the opening ceremony. I had to face both floods and very hot and dry conditions."
He added: "Londoners are very welcoming, the city is welcoming the whole world in a very nice way."
It was not possible to independently verify his account of his journey or how he managed to go through so many countries.
But the BBC showed footage of Chen displaying a passport filled with visas allowing him entry to countries along the route, as well as pictures of him with his three-wheeled vehicle at several international landmarks.
YouTube footage also appeared to show him in Rome in May.
He told the BBC he was inspired to make the journey while watching London mayor Boris Johnson accept the Olympic flag from inside the Bird's Nest stadium in Beijing at the 2008 closing ceremony.