Acquisition is essential to laser communication link′s establishing. In order to study the impact of optical aberrations on acquisition performances, based on the transmission process of beacon beam and image quality evaluation of laser communication system, the impact of monochromatic aberrations on acquisition centroid intensity and acquisition errors caused by tilt and coma with centroid and weighted centroid algorithm is analyzed as the root mean square (RMS) of monochromatic aberrations is less than 0.2λ. Besides, compensations between aberrations to the centroid intensity and acquisition errors are also discussed. The analysis reveales that acquisition errors caused by tilt (distortion) and coma can completely compensate for each other, and defocus can greatly compensate the centroid intensity decrease caused by sphere and astigmatism. The Cassegrain and three-mirror anastignat (TMA) antenna systems are designed by Zemax optical software, and by using the method, the combined effect of aberration on centroid intensity and acquisition errors within 0.3° circle field is calculated. The result can sufficiently support the above view. These conclusions can give some guides to antenna type selection and image quality optimization strategy in laser communication optical system design.