Authorities denied a passport to Ai, China's best known contemporary artist abroad, after detaining him for 81 days in 2011, apparently attempting to limit his international influence.
Police returned the document last week and the bearded conceptualist -- whose six-year-old son currently lives in Germany -- told AFP he had received the visa, without giving details.
Ai told the New York Times last week that he would travel to Germany "as soon as I get a visa".
Friends posted pictures of the document online, showing that it was valid for four years of multiple entries to the country, starting last Friday.
Ai last week published a photograph of himself clutching a red Chinese passport online, with the words: "Today, I received a passport," later confirming to AFP that it was his.
It is not clear whether having a passport and visa means Ai will be able to enter and exit China freely. Many Chinese dissidents have been detained at airports while trying to leave the country, while some activists who have left the mainland have found themselves not allowed back.
The Royal Academy of Arts in London said it expected Ai would travel to Britain ahead of his exhibition opening there on September 19th.
Ai's non-attendance at the event would have generated negative headlines just weeks before China's President Xi Jinping is due to make a high-profile visit to London.
The artist, who has released a heavy metal album and cites French artist Marcel Duchamp -- seen as the father of conceptual art -- as an inspiration, is known for his irreverent humour.
The burly son of a poet revered by China's first generation of Communist leaders, Ai helped to design the Bird's Nest Olympic Stadium for the 2008 Beijing Games, an event that brought the ruling party worldwide prestige.
But his outspoken criticism of China's leaders -- he has referred to them as "gangsters" -- and involvement in controversial social campaigns went on to make him a thorn in the government's side, and much of his work has been censored domestically.