Cops busted a 19-year-old college student at Trump Tower after the Secret Service found a hunting knife and a powerful firework in his backpack, police source said Tuesday.

Alexander Wang, who studies finance at Baruch College, told police he’s a big Donald Trump supporter who just likes to study for school at the billionaire President-elect’s home base.

Wang showed up at Trump Tower about 6:35 p.m. Monday and tried to get in at a checkpoint. When his bag set off the metal detector, the Secret Service moved in and asked him to open it.

Inside they found the hunting knife, an M-100 firework, a Swiss Army knife, a flashlight, handcuffs, an 8-foot black rope, a clear water gun, a laptop and a wire typically used to strangle someone called a garrote.

Wang was arrested by the NYPD for unlawful possession of fireworks and two counts of weapons possession — for the hunting knife and garotte.

He told investigators he’d never had a problem carrying his bag — weapons and explosives included — into the Midtown skyscraper the 10 or so prior times he visited, including two days after Trump won the presidency, sources said.

Read more from The New York Daily News.