Thor’s hammer may or may not be back in Avengers: Infinity War, Avengers: Infinity War is based on the Marvel Comics superhero team the Avengers, It is intended to be the sequel to Marvel’s The Avengers and Avengers: Age of Ultron and this will be the 19th film installment in the Marvel Cinematic Universe(MCU).
In Avengers: Infinity War, the Avengers join forces with the Guardians of the Galaxy to confront Thanos, who is trying to amass the Infinity Stones.
In one of the jaw-dropping moments from the Thor: Ragnarok teaser trailer, the mjolnir was destroyed by Cate Blanchett(Hela) with her bare hands. The trailer doesn’t explain at the moment how did thor recuperate from what happened and it is established that Hela will be dominating thor in the matter of second.
However, The Russo Brothers posted this picture through their official Instagram page, Showing that a priest is holding the legendary hammer, Mjolnir. With a caption that says “Worthy”. There is a possibility that this might only be a flashback or it can be that Doctor Strange uses his powers to put the hammer back together. At this point, there is no exact explanation as to why the hammer is intact again and how.