For the grating lobe and side-lobe suppression problem of distributed array aperture, a two-way pattern design method which is based on the distributed array structure and pattern multiplication theorem is proposed in this paper. The first step is to maximize the elimination of grating lobe and side-lobe by synthesis of the appropriate array factor and sub-array pattern functions; The second step is to suppress the remaining grating lobes by improving the transmitting pattern weight design according to the Minimax principle; Finally using separate transmitting and receiving arrays, a large aperture distributed array without the influence of grating lobe can be obtained based on the pattern multiplication theorem. Simulation results show that the method can effectively suppress the grating lobe and side-lobe in distributed array, and obtain the desired array pattern performance, which will help to improve the ability of radar detection.