A synthesis technique for the optimization of the element excitations of conformal phased array with improved NSGA-II (INSGA-II) algorithm is introduced in this communication. Firstly, the patterns of all the elements are measured in a microwave chamber when they are terminated by their own characteristic impedances. As these patterns called as active patterns are experimentally obtained, they have already included the mutual coupling information of the environment. Then the pattern of the conformal antenna array can be obtained by a superposition of all these active patterns with various weights. And because the pattern of each element has been pre-stored, one can avoid the full-wave numerous computations in the optimization process. Using the optimization algorithm, the weights including amplitude and phase of each element can be optimized quickly. Therefore this treatment has the advantages of less computation and high accuracy. In order to further accelerate the optimization, INSGA-II algorithm is applied. By using this algorithm, the entire optimal solutions, i.e., the optimal solutions of the main beam of the conformal phased array directing to different angles, can be solved at once. The idea is demonstrated through the designs of two conformal antenna arrays mounted on hemisphere and cylinder-hemisphere platforms, respectively. Comparisons between the experimental and simulated results show the effectiveness of the proposed approach.