应用换元法分解因式,不但能将问题化繁为简、化难为易,而且能拓宽思路、提高解题的技能技巧.现以近年来部分省市的数学竞赛题为例,归类介绍几种富有技巧性的换元法,供同学们参考. The use of the substitution method to factorize the factors can not only simplify the problem, simplify the process, but also broaden the train of thought and improve the skill of solving problems. Now the mathematical competitions in some provinces and cities in recent years are taken as examples. Several kinds of skillful substitution method for students to refer to.