The invention discloses a detection method of a laser beam state of a laser printer. The method is capable of rapidly and conveniently judging the position and the skew state of the laser beam by notusing special and complicated detection devices, rapidly determining whether the laser beam is horizontal or not or the deviation between a scanning line and the center is excessively high or not, effectively reducing the production cost in the production process, improving correction accuracy, rapidly determining the fault reason of skew of the printer in the after-sale maintenance process, judging the skew direction of the laser beam, providing a correction scheme about how to adjust the position of the laser device, reducing the maintenance time and the maintenance cost, improving the maintenance efficiency and improving the printing quality of the printer. The detection method of the laser beam state of the laser printer is wide in application range and high in utilization rate.