The invention discloses a PET (polyethylene terephthalate) substrate and application thereof and a PET functional plate lamination method. The PET substrate comprises PET resin, a PVC (polyvinyl chloride) cold-resistant softening agent and a maleic anhydride grafting compatilizer in a mass ratio of 70-90:1-3:2-5. The PET substrate is applied to a capacitive touch screen to serve as a PET functional plate. The method for lamination of the PET functional plate to the capacitive touch screen includes: S1, using the PET substrate for preparing the PET functional plate, and storing in a 35DEG C high-temperature electric warm box for standby application; S2, keeping the temperature of a low-temperature thermostatic chamber to be 10 DEG C, putting a glass cover plate in the low-temperature thermostatic chamber to reach room temperature thermal expansion and cold contraction indexes; keeping for standby application; S3, taking out the PET functional plate from the high-temperature electric warm box, and quickly laminating the PET functional plate and the cover plate on a lamination equipment in the low-temperature thermostatic chamber.