The invention provides a puller mechanism for laying PET under a silver film pasted to a FPC. A PET material roll winds around a second gas expansion shaft, a material belt of a silver film material is guided by multiple groups of guide wheels and passes through the second gas expansion shaft, then the PET material roll is laid under the silver film material, the front side of a mounting plate isprovided with a U-shaft mold rotary calibration pasting mechanism, after the silver film material being laid the PET material roll is punched and pasted through the U-shaft mold rotary calibration pasting mechanism, waste material of the silver film material is rolled into a silver film waste roll. According to the puller mechanism for laying the PET under the silver film pasted to the FPC, the PET material with the thickness of 2 mm is laid under the silver film material before the silver film material is punched and pasted, thus each punching and pasting part is provided with 2 mm width which is not pasted to a FPC product, when the product is subjected to hot pressing and drying oven operation, a silver film protective film can be easily torn off by using a blowing mode, the operation efficiency is greatly improved, the process waste is reduced, continuous automatic production operation can be carried out, the cost is saved, and the process management and control are easier to realize.