Abstract: In order to ensure the imaging quality of certain type telescope at assembly stage, an alignment method based on aberrations correction was proposed. The optical system model of this telescope was set up and the misalignment phenomena for every optical element was simulated to analyze the changes of aberrations, then the sensitivity matrix of optical element for aberrations was calculated and the best alignment scheme was determined to improve the assembly quality and efficiency.Finally the alignment experiment based on star test was conducted, the results show that the technique indicators are all satisfied after alignment and the resolution is better than required 7.5,which could validate the feasibility of our method and offer operability for the assembly and adjustment of this kind of instrument.