换元法是初中数学解题的一种技巧方法之一,它在解某些高次方程,无理方程及分式方程时,为了便于求解,把方程中的某部分换成新的未知数,从而达到高次方程降次,无理方程有理化,分式方程整式化的目的,在此笔者介绍在多年的教学实践和探索中,所得的几种巧用换元 The substitution method is one of the skill methods of the junior high school mathematics problem solving. When solving some high-order equations, irrational equations, and fractional equations, in order to facilitate the solution, a certain part of the equation is replaced with a new unknown number. To achieve the lower order of higher order equations, the rationalization of irrational equations, and the purpose of integral equations for fractional equations, here the author introduces several clever use of equivalences in years of teaching practice and exploration.