The invention relates to the field of non-flammable adhesive tape processing, in particular to an automatic pasting device for non-flammable adhesive tape. The automatic pasting device comprises an unwinding device, a cutting device and a workbench and further comprises an air expansion shaft, an absorption assembly, a pressing assembly and a limiting roll which is arranged above the air expansionshaft and can slide in the direction of the air expansion shaft. One end of the workbench is located at the downstream end of the unwinding device, and the air expansion shaft is arranged at the other end of the workbench. The cutting device is arranged below the workbench, a portal frame is arranged above the workbench in a crossing manner, and the absorption assembly is arranged in an opening of the portal frame. The top of the portal frame is provided with a translation electric cylinder for driving the absorption assembly to move in the direction of the air expansion shaft, and the pressing assembly is arranged on the side, away from the workbench, of the air expansion shaft. By means of the automatic pasting device, the cut non-flammable adhesive tape can be automatically and synchronously arranged on a paper roll in a wound manner, the manual winding link is omitted, and the production efficiency of a product is greatly improved.