函数的迭代在中学数学竞赛中经常出现 ,其迭代公式与应用也有不少文章论及 ,但多半是对某些整式或特殊的分式函数进行迭代 ,而一般的分式函数的迭代公式还鲜有谈到 .本文将从多项式理论的角度出发分析得出线性分式函数的ｎ次迭代公式 ,并通过实例说明其结论简捷实用 .定义　设 The iteration of the function often appears in the middle school math competition, and its iteration formula and application are also discussed in many articles, but most of it is to iterate over some integral or special fractional functions, and the general fractional function’s iterative formula is still fresh. Speaking. This article will analyze the n-iteration formulas of linear fractional functions from the perspective of polynomial theory, and illustrate their conclusions through simple examples.