Abstract: Because of low precision and local optimization of ultrasonic locating of partial discharge in transformer by using of traditional particle swarm algorithm, a kind of optimization method based on particle swarm algorithm and clonal selection method is proposed in this paper. The optimization model is built according to electroacoustic locating technique, and the particles are cloned and selected by the fitness to effectively maintain the population diversity, at the same time, the antibody is guided by updating the speed and position of particles to obtain the optimal solutions. In the end, the simulation are carried out by using of proposed method, and results are compared with those by using of PSO and GA approaches, which show that this algorithm has higher convergence speed and calculation precision that improves the correctness of locating.