The invention relates to the technical field of laser processing, and discloses an imaging system and method of a square scanning head of a dual-light-path dual-imaging visual galvanometer. The imaging method comprises the steps that external laser beams reach the galvanometer through a second lens, and act on a to-be-marked object through a first lens after being reflected by the galvanometer, and then the to-be-marked object is marked; a white light source emits an illuminating light path to brighten the to-be-marked object, the illuminating light path is reflected to the first lens, then partially reflected to a large-visual-field image acquisition module through the first lens, and used for acquiring the overall image of the to-be-marked object, coordinates of an image in a pre-marking position are obtained accordingly, the swinging angle of the galvanometer is further obtained, and the galvanometer is driven to rotate by the swinging angle; and part of the illuminating light path reaches the galvanometer through the first lens, enters a small-visual-field image acquisition module after being reflected to the second lens, and is used for acquiring detailed images of the to-be-marked object, and the accurate coordinates of the pre-marking position are obtained according to the detailed images. By adoption of the imaging system and method of the square scanning head of the dual-light-path dual-imaging visual galvanometer, the marking precision of the square marking head can be greatly improved.