A BBC investigation found universities received more than 700 allegations of sexual misconduct during the past academic year.
Students accused their universities of being paralysed by fear of reputational damage and not offering proper support.
Universities UK said institutions were making progress in handling complaints.
But students said they had to go through "traumatic" and lengthy complaints procedures, with one saying she "felt like the one on trial" and another calling it "a waste of time".
Freedom of Information responses obtained by File on 4 from 81 UK universities found more than 110 complaints of sexual assault and 80 allegations of rape were made last year.
In a number of cases students and universities also reported the alleged attacker to police.
However, there are no mandatory guidelines on how universities should investigate or record such complaints.
The result, campaigners and survivors say, is a "patchy" system that is failing students.
One student, who reported a violent rape to her university and police, was repeatedly forced to see her alleged attacker around campus because of a loophole in the university's safe-guarding procedure.
Women from multiple universities have also been dissuaded from coming forward on the grounds that the reporting process would be "traumatic".
One student said she was told by her university to spend the night in the library, after she told them she could not return to her accommodation out of fear of another attack.
Another described her experience as "like being 'gaslit' [a term for psychological abuse where victims are made to constantly doubt themselves and reality] on an institutional level".
Dani, 21, from the University of Cambridge, started having panic attacks after her supervisor sent her inappropriate and sexual messages.
On the verge of quitting her course, she tried to complain - but was passed around and given contradictory advice.
When she did manage to report it, she was warned eight times that she could face a harassment charge if she told anyone else about the allegations.
"Throughout the whole process I just felt like I was the one who was on trial," she told the BBC.
Before the disciplinary hearing, she asked to give evidence behind a screen - something commonplace in a court of law - but the university refused.
"I had to sit on the same side of the table just a couple of seats away from him, while I was cross-examined by his lawyer," she says.
Her complaint against him was upheld. But his punishment was to write a four sentence letter of apology and to follow a no-contact agreement that saw Dani - not her supervisor - barred from certain university buildings.
The man was allowed to remain at the university.
The University of Cambridge told the BBC it places the "utmost importance" on the welfare of its students and said improvements have, and will continue to be, made.