We present a new and efficient method for the design of dispersive multilayer by employing a particle swarm optimization (PSO) technique. Its mathematical background is given and an adaptive PSO is realized with computer code. Two practical designing tasks are solved with this method, and the obtained results are competitive compared with other published structures. The adaptive PSO method demonstrates its merits of fast convergence and powerful global search ability, and could be used as a valuable tool for the optical thin film design.