In view of the common skew of the printing image of a laser printer, the work aims to study and design the correction method of the printing skew based on the principle of laser printing. First of all, the laser printer's cartridge structure was used to make the test module, and the manufacturing method and working principle were introduced in detail. Secondly, a special test sample was designed. Finally, the test component was put into the printer and the test sample was printed. The laser beam position could be accurately tested and adjusted according to the proposed method so as to correct the skew of printing. This method can quickly and accurately test the position and skew state of the laser beam, and accurately correct the printing skew to the allowable range. This method is especially suitable for the debug of the prototype in the trial production stage and the maintenance phase of the product after sale.