A computation physics method is used here to deal with the problems of ion implantation.The Monte Carlo method is adopted as the simulated method.All complicated structure and component targets can be classified to three type of probability function formulations,Then, by direct Sampling method, ion implantation problems in those targets can be fransformed to the same problems in the simple average and single element targets,So, any type of complicated ion implantation problems can be calculated easely.A experienced formulation about how to determine the maximum impact parameter is also given here in this article.