Craig, who has enjoyed a successful television and business career after appearing in the first series back in 2000, said Big Brother had probably run its course, and it was time to find something new.
Programme maker Endemol and broadcaster Channel 5 this week stepped in to deny reports that the show would be cancelled this year.
Shropshire Star comment: It’s time to scrap this freak show Big Brother
The existing contract includes the "celebrity" series, which is being broadcast at the moment, the regular series featuring ordinary members of the public in the summer, and a further celebrity version later in the year.
But Endemol said talks were continuing about extending the contract beyond this year.
Craig said winning the series had changed his life, and he thought it was an excellent format, but he would not want to go on it today.
"People often come up to me and say they have applied for Big Brother or are thinking about it, and ask me what advice I would give them," he said.
"My honest advice is 'don't do it'.
"They say 'What? You did it', but I say that was a different show when I went on it.
"When we did it, we nobody knew how big it was going to be, we were just ordinary people and it was all quite innocent.
"Now everything has been engineered, the layout of the house, the tasks, the contestants they select, everything is designed to make people clash."
He added that he had met several of the celebrities who have appeared in the Celebrity Big Brother House. He said many of these had come across as perfectly pleasant people outside the house, but had not come across well when they appeared on TV.
Craig, who is due to marry fiancee Laura Sheriff at Peckforton Castle in Cheshire next month, said he had mixed feelings about the show today.
"On the one hand it massively changed my life, predominantly for the better, and it would be the end of an era if it was axed," he said.
"On the other hand, from a viewer's point of view, I think it probably is time for it to come to an end.
"I thought that when they said it was coming to an end before, when Channel 4 decided to drop it.
"When Channel 5 took it on, I thought that might give it some fresh ideas, but it hasn't, it's just continued to decline.
"I think we need a change of direction again, if you look at everything at the moment, Britain's Got Talent, X Factor, it is all about viewers voting, text messages and the internet, I think something new needs to happen.
"It's been on for 18 years, that's a long time, and it's probably run its course."
Craig won the hearts of the nation when he donated his £70,000 prize money to pay for a heart and lung transplant for his friend Joanne Harris, a Down's Syndrome sufferer from Shrewsbury. Sadly Joanne died in 2008 after falling ill with an infection.
Craig said that when he left the Big Brother house at the end of the first series, he had no idea how big the series had become over its 64-day run.
He said he was initially taken aback by the public interest in him, but went on to forge a successful career as a TV DIY expert, which included regular appearances on ITV's This Morning as well as his own BBC show Craig's Trade Tips.
The 46-year-old now has a multi-million pound property portfolio, and said the profile gained from his appearance on Big Brother had helped him focus on his passion for property makeovers.
But he said his greatest achievement was the platform it had given him in his charity work.
His Christmas 2000 charity single At This Time of Year reached No. 14 in the charts, and raised £40,000 for the Down's Syndrome Trust, and his appearance in the TV series Back To Reality raised a further £40,000 for Macmillan Cancer Relief.
He has since returned to his native Liverpool, but owns property in Newport and still returns to Shropshire.