10 Ways To Introduce Spider-Man To The Marvel Cinematic Universe

4. Say He's Been Working With S.H.I.E.L.D. All Along

There's no real reason to suggest that Spider-Man couldn't appear in a S.H.I.E.L.D. facility and be introduced to the Avengers as their new member by someone like Phil Coulson, having already established an association with them prior to that scene. Coulson could simply present him to the Avengers by saying "Spider-Man's been working with us for some time, but we kept it quiet to protect his identity" or something along those lines. Essentially, while S.H.I.E.L.D. obviously haven't been mentioned in the Amazing Spider-Man franchise, there is nothing in that franchise that directly contradicts the possibility that they may have had contact with him already. It's not as though having an association with S.H.I.E.L.D. means that every hero requires constant contact with them - look at Thor, Iron Man and Hulk, for examples of that - so the fact that Spider-Man hadn't been seen regularly working with them wouldn't be a problem.