A man robbed a trio of Brooklyn businesses at gunpoint during a three-day crime spree, police said Tuesday.

The first robbery happened just before 10 p.m. Sept. 23, at a fast food store on Ralph Avenue near Bergen Street in Bedford-Stuyvesant, police said.

The unidentified crook ordered a cheeseburger at Crown Fried Chicken, then pulled a pistol and demanded the cash from the register, cops said.

He got away with around $630, police said.

Two days later at around 2 p.m., he stole $50 from Etoman Beauty Supply at 347 Ralph Ave., again ordering something from the person at the register, then pulling a gun and demanding cash, police said.

The third robbery happened at a Metro PCS store at 455 Sutter Ave. in Brownsville, just before 2 p.m. Sept. 26. The bandit pulled the same scam — he asked an employee about cellphones, then pulled a gun and demanded items, police said.

That time he got away with an iPhone and an LG Stylo Plus, according to police.

No one was injured in any of the robberies, cops said.