The present invention provides an anti-peeping device comprising: a plate-shaped substrate; a magnetic field generating device disposed on the plate-shaped substrate for generating a magnetic field; a plurality of light blocking walls deflectably connected to the plate-shaped substrate and configured to be changeable in its deflecting direction and/or deflecting angle in response to a change in a direction and/or an intensity of the magnetic field; a magnetic field control device; and a user input device for receiving an instruction from a user. The magnetic field control device is configured to control the magnetic field generating device to adjust the direction and/or the intensity of the magnetic field based on an instruction received from the user input device, so as to change the deflecting direction and/or the deflecting angle of the light blocking walls. The present invention further comprises a control method for an anti-peeping device.