Maximum modulus principle plays an important role in the complex analytics, and it is a powerful tool in studying the analytic function. 摘要最大模原理在复变函数论中占有重要的地位，是研究解析函数的有力工具。
Classical complex variable method is followed, but a new conformal mapping formula is proposed so that the exterior part of the parabolic crack is mapped into a unit circle. 采用了传统的复变函数保角映射法，给出了一个新的保角变换公式，从而将抛物线曲裂纹外的区域映射到一个复平面的单位圆内。
