Light weight design is still a critical technology for next generation aircraft. Either from the general design or the potentical benifit on carbon emission, the data show that the composite material will be increasingly deployed in new aircraft from the aspect of green aviation, so related design method or optimization method are still needed to achieved ultimate weight reduction. This article proposes a genetic algorithm based on strain neighborhood which takes the strains of the upper and lower wing finite elements as datasets. In these datasets, several higher strains will appear making themselves the cluster centres. Based on the positions of these elements and the four-connectivity rules, the elements with monotonic changes in strain values and common edges will be divided into a strain neighbourhood. The elements within the strain neighborhood are optimized as a whole, reducing the number of design variables and thickness variations between adjacent elements and also reflecting the continuity of force transmission, improving the continuity and smoothness of the skin laminate.