The pressure reducing regulator which was the key point of turbo-pump gas-sealed decompressing experiment system was optimized by PSO(particle swarm optimization).Uniform design was used twice before the optimization for the sake of reducing computing quantity.The structure parameters of pressure reducing regulator were optimized to obtain steady outlet pressure meeting engineering requirement.The result indicates that the range of variables was compressed availably through twice of the uniform design.Compared with initial point

the swing of outlet pressure decreases obviously according with engineering design.