After analyzing the load transfer law of pile, points out the bearing capacity of single pile has undergone the process of occurrence, development, maturity and saturation under the pile top static loading. Using the biological growth views, applies the Logistic function models to predict the ultimate load of single pile, and gives the particle swarm optimization (PSO) method for its parameter estimation. Through a case analysis, compares the PSO-Logistic prediction model with common used models. The results show that: the curve of pile load-settlement can be decrypting by Logistic function and it has high prediction accuracy.