我们把平面上到两定点的距离之和是常数的点的轨迹称为椭圆,这两个定点称为椭圆的焦点。当两个焦点无限接近时,椭圆就趋近于圆。换句话说,圆也可以看成是离心率为零的特殊的椭圆。由此可见,圆与椭圆二者之间有着密不可分的联系。本文通过椭圆与圆的类比探究,帮助我们加深对圆与椭圆的理解与掌握。对于平面上任意一个圆,按其某条直径进行伸缩变换就可以得到椭圆。因此,只要我们选择适当的变换形式就可以实现圆与椭圆图形之间的相互转换。 We call the trajectory of the point where the sum of the distances to two fixed points is constant and are called ellipses. These two fixed points are called the focal points of the ellipse. When two focal points approach infinitely, the ellipse approaches the circle. In other words, a circle can also be thought of as a special ellipse with a zero eccentricity. This shows that the circle and the ellipse are inextricably linked. In this paper, through the analogy between ellipse and circle, we can help us deepen the understanding and mastery of circle and ellipse. For any circle on the plane, according to the diameter of a telescopic transformation can be obtained oval. Therefore, as long as we select the appropriate transform form can be achieved between the circle and the ellipse graphics conversion.