Abstract: When using the existing typical algorithm to solve the model of optimizing irrigation schedule,with each algorithm itself having the insufficiency,the acceptable optimal solution of the model is usually not able to search successfully.The free search (FS) is a novel optimization algorithm.As an illustrative case,the article modifies it properly and applies it to solve the model of optimizing irrigation schedule at the different water supplies.The results obtained suggest that FS has favorable stability and convergence and can give a more accurate solution to the dynamic programming successive approximation (DPSA),genetic algorithm (GA) and chaos algorithm (CA) FS has clear regulation and convenient operation,and is a better method for optimizing irrigation schedule.