The fashion designer, who will join a delegation of 10 CEOs from the world's biggest companies in Cornwall, told Sky News she will be asking the world leaders to "look at laws, look at policy change" so that she no longer feels "penalised for doing good".
The prince has described it as a "potentially game-changing opportunity" for governments and the private sector to share ideas on how they can work hand in hand to build a sustainable future.
Speaking to Sky News ahead of the event later, McCartney said she was excited but also slightly terrified by the enormity of the moment.
She said: "I see it as a really powerful opportunity for me to actually bring light to an industry that I think has gone under the radar of late, or forever, on sustainable issues.
"I don't think anyone really knows that the fashion industry is one of the most harmful industries.
"I don't think they know that 150 million trees are cut down for viscose whereas I've managed to source a sustainable wood pulp in Sweden.
"I don't think people know anything about it, so for me to be there with these world leaders is really exciting, but also very terrifying because I'm desperate to get across some of the facts and realities of how unfashionable the fashion industry is."
The daughter of Beatles legend Paul McCartney and Linda McCartney, photographer and animal rights activist, she graduated from fashion school in 1995 and after working as creative director for Chloe in Paris launched her own fashion house in 2001.
A lifelong vegetarian, she has never used leather, feathers, skin or fur in any of her designs since day one.
But at the moment McCartney says she is "penalised" through taxes and regulations for trying to be green in the way she produces her clothes.
Asked what action she wants to see from government and what she'll be asking for from the leaders, she said: "I'm kind of here to encourage these world leaders to really look at laws, look at policy change, how to incentivise the young designers of tomorrow, the young fashion houses.
"I'm not incentivised at all, in fact I can be hit by up to a 30% tax if I export a non-leather good into the United States of America and I have to put that in my margins and that doesn't help me as a business and I'm penalised for doing good if you like.
"If I put a slither of pig leather onto that vegan product, my tax is exempt. So these are the kind of conversations I want to have, I want to be encouraged to work this way... we want to have policy change, and you know I'm excited to try and get that message across."
In the past 18 months the Prince of Wales has convened groups of business leaders to talk about what practical changes could accelerate the push for net-zero emissions.
The CEOs going to Cornwall are representative of the 300 business leaders who have signed up to his "terra carta", or earth charter, a set of principles that it's hoped will provide a roadmap for a sustainable future.
It includes more targeted investment in innovative green technology and more joined up thinking between countries when it comes to setting targets in areas such as electric vehicles.
For more than 20 years, McCartney has been committed to working in an environmentally friendly way, but she says the small innovative suppliers she works with need investment to scale up production or other retailers can benefit and the costs can come down.
That's why she believes that this business talking shop convened by Prince Charles could be so beneficial, with the financial industry bringing the capital they need.
But she also believes shoppers have a huge role to play, in encouraging the industry to speed up its commitment to sustainability.
She said: "There are loads of great ways to be sustainable in fashion, the consumer is really the one driving this. You know I serve the consumer, I firmly believe that.
"And I know the younger consumer, most consumers now if they know the harm that industry is doing to deliver these products, I don't think they want to be part of it. You can rent clothes, you can resell clothes, you can have second hand clothes, you can use charity shops."
Prince Charles, who has campaigned on environmental issues for more than 50 years, will be joined by Prince William, who is also a committed conservationist, for the reception at the Eden Project.