关键词: 平行板电容器, 直缝隙, 施瓦茨-克利斯多菲变换, 耐压能力, 电容量 Abstract: The electric field of a parallel plate condenser of polar plate with straight gap is studied by using the Schwarz-Christoffel transformation in the coordinate system of the complex number, and its electric potential distri- bution and electric intensity distribution are obtained.