A science teacher is suing the city and Department of Education, claiming she was canned from a Brooklyn school for refusing to let a student cheat on a Regents exam.

Ivy Lin, 34, of Queens, was proctoring the Living Environment test at New Utrecht HS in Bensonhurst in January and refused to accept the test paper of a student who had taken extra time to complete the exam, and said he had been given the time by another teacher.

When a fellow science teacher asked Lin to accept the senior’s exam, she again refused and that teacher called her a “f–king bitch,” Manhattan Supreme Court papers allege.

A second teacher said the student “really needs to get out of here and graduate,” and a third told her, “Keep quiet about this. Trust me. They don’t like people who make a fuss here,” according to Lin’s suit.

Lin, a nontenured teacher working for the DOE since 2007 who was making $65,000 a year, complained to the principal, and a campaign of harassment ensued, her suit claims.

She says she was fired in June for missing too many days of school, even though she’d been hospitalized after being hit by a car.

Lin wants her job back, plus back pay.

A city Law Department spokeswoman said she just received the legal papers and is reviewing the claims. A DOE spokesman declined to comment on Lin’s termination because of the pending litigation.