Device and method for preventing film from being secretly filmed

The invention discloses a device for preventing a film from being secretly filmed, the device comprising an infrared laser (2), an electric actuated piece (3). The infrared laser (2) fixed on the electric actuated piece (3) is used for emitting infrared lights to a screen (4). The electric actuated piece (3) is used for making the infrared lights emitted by the infrared laser (2) fixed on the electric actuated piece (3) generate deviation according to a received drive signal action. The method for preventing film from being secretly filmed comprises the following steps: a) using the infrared laser (2) to emit the infrared lights to the screen (4), the infrared laser (2) being fixed on the electric actuated piece (3); and b) driving the electric actuated piece (3) to operate, so as to make the infrared lights emitted by the infrared laser (2) fixed on the electric actuated piece (3) generate deviation. With the device and the method for preventing the film from being secretly filmed, piracy and secrete filming can be effectively prevented with high security and low cost.