化参数方程为普通方程是中学数学的一个难点 ,其基本方法大致有代入消参 .加减消参、代数恒等式消参、三角恒等式消参等 .由于它涉及知识点多 ,又要求具有一定的运算技能和代数式变形的技巧 ,因而也是数学中的一个难点 .本文给出形如　ｘ =Ｘ(ｔ)Ｘ′(ｔ) ,ｙ =Ｙ(ｔ)Ｙ′(ｔ) The parametric equation is a difficult problem for middle school mathematics, and its basic methods are roughly substituted into the parameters. Addition and subtraction parameters, algebraic identity equations, trigonometric identity equations, etc. Since it involves a lot of knowledge, but also requires a certain Computational skills and algebraic deformation techniques are also a difficulty in mathematics. This paper gives the form x = X(t)X’(t), y = Y(t)Y’(t)