高中物理竞赛中,在研究“质点或质点系、刚体绕某一定点或轴线运动”这类问题时,常常利用角动量守恒定律来处理此类问题.近期,在高中学生的竞赛培训中,笔者选择了此类问题作为测试题,发现初学者由于对定律的应用条件及角动量的概念模糊不清,有一些“想当然”或似是而非的错误.本文以一题的错解分析和多解研究来阐述应用角动量守恒定律时要注意 In the high school physics competition, we often use the law of conservation of angular momentum to deal with such problems as the “particle or particle system, rigid body movement around a fixed point or axis.” Recently, in the competition training for high school students , I chose such questions as test questions and found that beginners due to the application of the law conditions and the concept of angular momentum ambiguous, there are some “paradox ” or plausible errors.This article with a question of misunderstanding and Multi-solution study to illustrate the application of conservation law of angular momentum to pay attention