Last seasonâ€™s Johnny Warren Medallist signed the paperwork in the last few days and it looks increasingly likely that he will play against the Jets in the Asian Champions League.
Beijing and Newcastle have drawn each other in Group E of the competition and a loophole in the strikers contract will allow him to play when the two clubs meet in China but he is banned from playing in the clash in Australia.
Griffiths management said getting the deal to go China was extremely difficult but also suggested that the Jets marquee player may make his move a permanent one.
"It was too good an offer for him to refuse," said his agent Ante Alilovic of Entourage Management.
"He's 29, he's got a kid on the way and he's not got too many big paydays left. He said he had to go and take it.
"Newcastle weren't willing to part with him though. It didn't actually look like the deal was going to go through. It was the hardest deal we've ever done.
"He's going to be very comfortable there - Beijing's actually a very nice place," added Alilovic.
"His brother's there so they'll both be playing for the same team. He's going to be very happy there."