The invention discloses a control method of an adjustable weeding machine. The method comprises the following steps that A, one end of a shell is provided with a pull rod, the bottom of the shell is provided with rolling wheels; B, the shell is provided with an adjusting rod, the adjusting rod is internally provided with a sliding block, and the sliding block is provided with a threaded rod; C, the sliding block is provided with a mounting seat, the mounting seat is provided with a gasoline engine, the gasoline engine is connected with a connecting rod, one end of the connecting rod is provided with a weeding blade; D, a driving device drives the threaded rod to rotate to adjust the height and location of the weeding blade. The control method of the adjustable weeding machine has the advantages that the driving device drives the threaded rod to rotate, so that the sliding block moves vertically to adjust the height and location of the weeding blade, thereby the weeding machine can be suitable for different ground conditions; the adjustment process can be achieved through the operation of a controller, the time and labor are reduced, and the weeding machine is convenient and reliable.