The group reportedly had around 9,500 members and also contained posts mocking migrant deaths.
Posts in the group included one that encouraged officers to throw a “burrito at these b*****s”, while others said “f***k the hoes” and “There should be no photo ops for these scum buckets”, ProPublica reported.
Another included a doctored image that showed Ms Ocasio-Cortez performing a sex act on Donald Trump. A caption accompanying the image read: “That’s right b*****s. The masses have spoken and today democracy won."
There was also a post suggesting an image of a migrant father and his toddler drowned on the banks of the Rio Grande was fake and referred to them as “floaters”.
Carla Provost, the Border Patrol chief, called the posts on the Facebook group "completely inappropriate".
"Any employees found to have violated our standards of conduct will be held accountable," he said.
Ms Ocasio-Cortez condemned the group, tweeting: “9,500 CBP officers sharing memes about dead migrants and discussing violence and sexual misconduct towards members of Congress.”
How on earth can CBP’s culture be trusted to care for refugees humanely? PS I have no plans to change my itinerary & will visit the CBP station today.”
On Monday, the Democratic congresswoman visited a migrant centre in Texas alongside members of the Congressional Hispanic Caucus.
Ms Ocasio-Cortez described conditions inside the facility as “horrifying” and said the migrants were treated “like animals”.
She claimed that Border Patrol officers had told women in cells to “drink out of the toilets” and used “psychological warfare” to intimidate and torture detainees.
Earlier this month, Mexico reached a deal with the Trump administration to try to stem the flow of undocumented migrants travelling to the US. Since then, deportations and detentions of undocumented migrants have reportedly increased.
Last week, the US senate approved a $4.5bn (£3.5bn) humanitarian aid package for the US-Mexico border.
It comes after a photo of a drowned man and his daughter in the Rio Grande last week brought the migration crisis into sharp focus.
The Border Patrol agency also came under after hundreds of migrant children were transferred out of a filthy border station in Texas where they had been detained for weeks without access to soap, clean clothes or adequate food.
Ms Ocasio Cortez is due to visit the facility in Clint on Tuesday. “This has been horrifying so far. It is hard to understate the enormity of the problem,” she tweeted ahead of the visit.
“We’re talking systemic cruelty w/ a dehumanizing culture that treats them like animals.”
Additional reporting by AP