作者李成章.添加辅助圆,在平面几何的证题中是常用的一种方法.那么,这一常规方法在解竞赛题时作用又如何呢?本文通过引入辅助圆,巧妙地解了连续六届IMO的7道竞赛题,思路简洁,解法新颖,易于掌握.这些题目的解法说明,引入辅助圆这一常规方法是十分有用的证题技巧,用来解难度较大的竞赛题同样可以奏效. Author Li Chengzhang. Adding an auxiliary circle is a commonly used method in the plane geometry. Then, what is the role of this conventional method in solving contest problems? This article has cleverly solved the continuous six by introducing auxiliary circles. The IMO’s seven contest questions, the idea is simple, the solution is novel, and easy to master. The solution of these topics shows that the introduction of the auxiliary circle is a very useful method of examination questions. It can also be used to solve difficult competition problems. .