In order to analyze the influence mechanism of typical interference factors on the surface profile accuracy in ultra-precision turning process and the characteristics of surface profile errors caused by these interference factors,a single point diamond turning experiment was carried out on Al6061 samples based on the self-developed ultra-precision machine tool Nanosys600.Through the iterative process of cutting,profile measurement,profile filtering and analysis,the error sources in the machining process were identified and investigated.After adjusting the ambient temperature and changing the working area of the guide rail,the peak-to-valley value of the filtered profile was reduced from 1 510 nm to 203 nm.