The 39-year-old was whittling her Overs category from 20 to six when she was apparently booed by the crowd for making some tough decisions.
The brunette beauty is said to have walked off the set when things became too much, leaving the audience shocked.
An X Factor source revealed: "Nicole left the set upset as the situation was so intense and it all got too much for her.
"It was a long and stressful day and it wasn't helped by the fact the crowd were not on Nicole's side for some of her choices.
"Before filming had commenced, the audience were encouraged by the show's production staff to be vocal about what they thought of her choices.
Nicole reportedly walked off set during filming for the latest series of The X Factor
Sharon was also reportedly left in tears after the six chair challenge
Nicole left the set upset as the situation was so intense and it all got too much for her
X Factor insider
"They took this on board and were very loud, but unfortunately for Nicole at times it did mean a deafening shower of boos and jeers," the insider told The Sun.
The source added that Nicole was comforted backstage by X Factor staff, who reassured her that she was doing the right thing.
They continued: "Nicole was very upset and had to be reassured by show's producers she was making the decisions that she felt were best.
"At one point some were concerned that Nicole might not come back on stage because she was that upset. Despite Nicole being a seasoned judge, they believed she was finding the process more difficult than ever.
"The boos from the audience reached their peak when one popular contestant was dumped by Nicole. She later changed her mind and decided to send them through to judges' houses," the insider said.
Sexy Nicole Scherzinger in pics
Mon, July 17, 2017
Ex-pussycat doll and X Factor judge Nicole Scherzinger flaunts her fabulous figure.
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Nicole Scherzinger displays sensational figure in hot pink bikini
This comes as the six chair challenge has reportedly gone through a shake-up meaning that each judge is left alone to make difficult decisions by themselves.
Sharon Osbourne, 64, was reportedly reduced to tears by the same challenge earlier this week after facing backlash from the audience for her decisions.
Express.co.uk had contacted a representative from The X Factor for comment.