Spider-Man is part of the Marvel Cinematic Universe now, however, there are still some uncertainties about how that will work out in the long term, and what exactly the complicated deal between Marvel Studios and Sony entails.
That said, looks like the deal extends for at least five movies right now – one of which is going to be Avengers 4. Marvel Studios President Kevin Feige recently discussed quite a lot about the future of the MCU with reporters, and one thing that was confirmed, is that Tom Holland will indeed be reprising his role as Spider-Man in Avengers 4.
Kevin Feige confirmed that the deal with Sony will allow for Spider-Man to be part of the MCU for the upcoming Spider-Man: Homecoming, as well as a sequel that is already slated for July 5, 2019. Kevin Feige also confirmed that Marvel is not involved with the spin-offs set in the Spider-Man universe, such as the R-rated Venom movie and the Silver Sable and Black Cat movie.