The embodiment of the invention provides a device and a method for optical alignment, belongs to the field of optical alignment display, and solves the problem of poor picture effect after a large liquid crystal panel is irradiated by UV (ultraviolet). The optical alignment device comprises an ultraviolet lamp staggering unit and a shielding plate adjusting unit, wherein the ultraviolet lamp staggering unit comprises at least two ultraviolet lamps which are staggered and butted, the shielding plate adjusting unit comprises at least one movable shielding plate, and is used for adjusting the position of the shielding plate, and the shielding plate is used for shielding the light of a staggering area formed by the staggering and butting of the two ultraviolet lamps. The optical alignment device can be applied to the optical alignment technology of the liquid crystal panel.