负迁移会阻碍新的知识技能的形成,学生学习中经常出现的难点、错误和问题,不少是因为负迁移的规律引起的.初中时学习的“圆的切线”概念,由于负迁移的作用,会对后来学习一般曲线切线的概念产生消极影响,本文通过具体的例子,分析学生在概念理解中出现的各种错误原因,帮助学生正确理解切线概念,形成正确的知识结构. Negative transfer will hinder the formation of new knowledge and skills, difficulties, mistakes and problems frequently encountered in student learning, many of which are caused by the law of negative transfer. The concept of “round tangent” , This will have a negative impact on the concept of later learning general curve tangents. Through specific examples, this paper analyzes the various error reasons that students appear in the conceptual understanding to help students correctly understand the concept of tangent and form the correct knowledge structure.