Abstract: Hybrid Particle swarm optimization (HPSO) algorithm is a stochastic global optimization technique with many advantages, such as quick convergence, simple regulation and easy implementation. In order to determine the multi-parameters of cement fly-ash gravel (CFG) pile composite foundation, in this article, a new method is presented using HPSO algorithm and fish language, which was contained in FLAC. At first, the stochastic values of parameters are initialized and the quantity of CFG was regarded as fitness function to evaluate quality of the parameters. Then the parameters are updated continually using HPSO until the optimal parameters are found. Thus parameters of CFG pile composite foundation are identified adaptively during computation. This method was used in the design of CFG pile composite foundation in a project, and the results show that HPSO algorithm is effective in designing of cement fly-ash gravel pile composite foundation, which can reduce engineering cost and increase economic efficiency effectively.