Disclosed is an auto-darkening filter (1) comprising: at least one liquid crystal sheet (1), two polarizing sheets (13) separately disposed on two sides of the liquid crystal sheet (11), a driving circuit (15) driving the liquid crystal sheet (11), and an angle adjusting device (17), wherein the at least one of the polarizing sheets (13) is configured as a rotatable movable polarizing sheet for changing an angle between transmission axes of the two polarizing sheets (13), the angle being adjusted by the angle adjusting device (17). In the auto-darkening filter as provided, at least one polarizing sheet is configured as a rotatable movable polarizing sheet, which enables adjustment of the angle between the transmission axes of two polarizing sheets； by rotating the movable polarizing sheet 0°∼5°, the visible light transmittance of the auto-darkening filter may vary in a range of 10-6 to 10-1； additionally, the driving circuit works in a high-voltage and low-frequency manner, which may lower the cost, reduce power consumption of the circuit, and meanwhile improve the viewing angle response property of liquid crystal.
