The control of mid-frequency error of optical surface has been a hot and difficult problem in optical processing field for a long time.For computer controlled optical surfacing technology,traditional processing paths such as grating path and spiral path usually introduce inherent mid-frequency frequency error,while the new pseudo-random path requires too much dynamic performance of machine tools to make it difficult to be widely used.Based on the study of pseudo-random trajectory,this paper proposes a method to suppress the mid-frequency error of optical surface by using pseudo-random Rose trajectory.On the basis of ensuring the non-coincidence of machining paths and traversing the optical surface,the parametric model of pseudo-random Rose trajectory is established.A comparison experiment was carried out between the traditional processing trajectory and pseudo-random Rose trajectory,and the interference results were analyzed by power spectral density.The experimental results show that the three paths can effectively suppress the low-frequency error,while the traditional path has a negative impact on the frequency band error of more than 1/0.07 mm,while the pseudo-random Rose trajectory can effectively suppress the mid-frequency error.