The optimization of the parameter estimation of optimal line method in Hydrological frequency analysis, such as the application of the artificial intelligence algorithms which includes the ant colony algorithm, genetic algorithm, particle swarm optimiza - tion, simulated annealing algorithm and other methods, is difficult to determine the model parameters and the optimization result is not stable, namely, the defect of premature convergence. This paper expounded the basic principle of the social spiders optimization algorithm systematically, and put forward that the social spider optimization algorithm should be applied to hydrological parameters of frequency curve, and at the same time be compared with the traditional parameter estimation method (moment method, weight function method, probability weighted moment method, and genetic algorithm). It was showed that in this method the search efficiency is high, the result is stable and the global optimal solution of parameters can be can found out.