The influence of phase-only encoding method on the generation of circular Airy beams is investigated and the commonly used coding method is discussed in detail, which is compared with the other introduced encoding method. The results show that both methods can be used to produce high quality circular Airy beams. The beam generated by the commonly used method has a good quality, little affected by beam parameters, and has a wide application. Although, the quality of the beam generated by the other method is relatively poor, which is also dependent on beam parameters, the diffraction efficiency is high, 2.4 times that by the original method, which indicating that there exist many advantages on the applications of laser processing, nonlinear excitation, and so on. The circular Airy beams are generated experimentally by both methods. The experimental results show that the quality of the beam generated by the commonly used method is affected seriously by the background noise due to its low diffraction efficiency, while the beam generated by the other coding method is well consistent with the theoretical result and its feasibility is experimentally confirmed.