Need to qualify first, and contact the person in charge of your area. please contact with the related department. For the contact details please refer to: http://cief.cantonfair.org.cn/en/international/contactus.aspx.
To book a stall at the Canton Fair, you will need to fill out an application form and submit it to the organizers. You will need to provide information about your company and the products you wish to exhibit. Once your application is approved, you will be able to confirm your booking and pay the fees.
https://cief.cantonfair.org.cn/en/international/index.aspx