The problems of slow convergence speed and being prone to converge to minimum were solved by combining the characteristics of chaos dynamics in the paper, whose characteristic of combining chaos optimal ergodicity and particle swarm optimal rapidness conquered deficiency of the traditional PSO algorithm. The proposed algorithm used for the decelerator of the electric submersible progressive cavity pump (ESPCP) design optimization compared with that of which was based on the standard PSO and genetic algorithm. By use of property mentioned, optimization searching could be carried out, firstly a series of chaos variables were produced as same number as optimization variable, then chaos was lead into optimization variable by the way of similar to carrier, that made the optimization variable into a chaos state, at the same time, the extent of chaos emotion was magnified to the value range of optimization variable, at last searched by chaos variable, searching technique based on chaos had more superiority than other searching technique. The results showed that the proposed algorithm was superior to the other two algorithms with a better astringency and stability. This article offered a new optimization method in machine.