10/11 8:33 AM PT -- Security is already super heavy outside The Grove Wednesday morning ... with barricades and security guards all over the place.

We're told it's next to impossible to get inside the shopping center, and the security presence is only going to grow.

Taylor Swift's power knows no bounds ... a world-famous outdoor mall is shutting down for the entire day Wednesday for the world premiere of Taylor Swift's "Eras Tour" flick!

The Grove -- which has become a Los Angeles institution -- will host the unveiling of the highly-anticipated film for 2,200 lucky fans in its 14 AMC theaters.

We're told Taylor's team has invited the fans and they will receive details on where and when to show up at around 2 PM Wednesday.

Guests will arrive at 6 PM and the movie starts at 7 PM.

Security will be out in full force -- that includes the LAPD and L.A. Fire Dept. -- to make sure no one other than invited guests gets in. Barricades were set up late Tuesday night.

As for the presumed guest of honor -- we don't know if Taylor will show, but if we had to guess ... given the planning and secrecy, our money is on her showing up.

We're told The Grove's owner, Rick Caruso, and his company will be compensating all the small businesses that are losing profits from the shutdown.

Taylor's movie is already a monster hit, surpassing $100 million in presale tickets across the globe ... so Wednesday's premiere will be a night to remember.