How to effectively correct ocular aberrations which vary largely from person to person and improve the application scope of adaptive optical system for human retinal imaging is the biggest problem in the clinical application. Rotating cylinders provide a flexible method to correct astigmatism at low cost. This study provides the theoretical basis of rotating cylinders for the astigmatism compensation and an experimental system of automatically correcting astigmatism is established based on the far-field facula analysis to prove the theoretical basis. Then the rotating cylinders are combined with an adaptive optics system and the real-time wavefront is measured by the Hartman-Shack sensor to guide rotating cylinders adjustment. The modified system could compensate the astigmatism aberration automatically from -4 to 0 Dc with residual error lower than 0.1 Dc. Combined with the Badal lens, this system provides an economical and effective method to compensate low aberrations for large-scale clinical applications of adaptive optical system for human retinal imaging.