In this paper, the genetic algorithm (GA) combined with ray tracing (RT) method is employed to simultaneously optimize the boresight error (BSE) and power transmittance of the 3D A-sandwich radome. The thicknesses of the skin and core layer of the radome wall are chosen as the optimal parameters, and minimizing the BSE and maximizing the power transmittance of the antenna-radome system are the objects. A new structure of local uniform thickness radome, which is more easily to be fabricated than the traditional variable thickness one, is proposed for the multi-objective optimization. The BSE of the optimal antenna-radome system is reduced significantly and the power transmittance of the radome is also improved.