The invention discloses a method for adjusting spiral shear blades of a roller type flying shear. A common and easy method that whether paper is cut off or not is utilized for observation, and then the spiral shear blades of the roller type flying shear is adjusted. According to the adjusting method, a side gap and a gap of the spiral shear blades can be effectively adjust, so that the shearing quality of the sheared workpiece is improved and the service life of the roller type flying shear are greatly prolonged.