Abstract: Aiming at the antenna sharing requirement of mobile combat platform, this paper proposes a planar array antenna aperture allocation method for radar communication integration. Firstly, the shared aperture model is established on the basis of planar array; secondly, the allocation of array element position is transformed into a multi-objective optimization problem, and the maximum peak side-lobe level of radar array pattern and channel capacity of communication array element are selected as optimization objectives; finally, the improved genetic algorithm is used for optimization calculation, and the related simulation experiments are completed. The simulation results show that the maximum peak side-lobe level of radar and the capacity of communication channel can meet the working requirements at the same time, and the antenna aperture can be shared.