The invention discloses a passive squeezing and cutting type thin film cutting off device, which relates to a thin film use device. In the prior art, a thin film is rolled and placed in a paper box, so that the thin film is dangerous and inconvenient to be cut off by an iron sheet toothed bar at a corner of the paper box after being pulled out. The passive squeezing and cutting type thin film cutting off device is composed of a convex cutter and a concave cutter; the convex cutter is composed of a serrated knife, a front convex squeezing block and a rear convex squeezing block; the concave cutter is composed of a knife groove, a front concave squeezing pit and a rear concave squeezing pit; the convex cutter is fixed at a front side over the top of the paper box body, and the concave cutter is fixed at the front side under the bottom of a box cover; a group of open and close pivots capable of opening and closing in rotation are arranged at the top of the box body and the bottom of the box cover so as to connect the box cover and the box body together, and the distance from a transverse center line of the open and close pivots to the transverse center line of a section of the serrated knife is equal to that from the transverse center line of the open and close pivots to the transverse center line of the section of the knife groove. The passive squeezing and cutting type thin film cutting off device can conveniently cut off the thin film without any danger, cannot deform in long-term use, and enables the thin film to be smoothly pulled out while being used again.