Kate Gosselin‘s divorce from husband Jon is turning vicious – she’s set to use shocking videos and photos to keep the kids and grab their multimillion-dollar fortune, The ENQUIRER has learned exclusively.

The split could become the mother of all divorce battles as Kate has grown increasingly appalled at Jon’s new romances – and wants her children nowhere near the kind of women Jon chooses to date, say sources.

Kate is rolling out the heavy ammo, which includes videotapes of Jon and 22-year-old Hailey Glassman on a secret date in May, numerous photos and videos of Hailey using drugs and getting drunk.

And as The ENQUIRER previously reported, Hailey’s college friend claims she had a three-year lesbian relationship with her.

What’s more, livid mom Kate is also ready to unleash accounts of another of Jon’s squeezes, 26-year-old party girl “star” reporter Kate Major, whose wild lifestyle gives Hailey’s past some competition.

At stake for Jon is custody of his children – and a fortune estimated to be as much as $10 million.

“Kate feels Jon is acting like a college frat boy, making horrible choices in girlfriends, and she is on a mission to take every dime – and the kids,” revealed an insider.

Jon and Kate get a reported paycheck of up to $75,000 for each TV episode – approximately $1.7 million a year.

They also pull in $20,000 per speaking engagement and make up to 25 appearances a year – for another $500,000.

Kate’s book Multiple Blessings is a huge success, and her contract with her publisher for her new book, 8 Little Faces, will bring her from $4 million to $8 million this year, according to publishing sources.

She also gets up to $100,000 a year for autographed photos, and the Gosselins receive numerous “freebies” – valued at as much as $500,000 annually.

“Jon better get his act together, or he will lose his money AND his children!” the pal concluded.

Bottom line: JK8 producers best keep ratings for flagging show up – by ANY means necessary! New eps begin airing tonight.