This article introduces a modeling method for the reverse biased electric field of junction barrier Schottky (JBS) diodes, utilizing the Schwarz-Christoffel transformation. Building upon prior research on JBS diodes electric field modeling, this approach is rooted in a purely theoretical derivation, avoiding the dependence on conclusions from simulation software—a limitation of earlier modeling methods. In this study, complex boundary conditions are transformed mathematically into simpler ones to make it possible to solve for the electric field. Then, the analytic solution of the electric field distribution is obtained by using the superposition theorem. To validate this modeling method, the electric field distribution from this model is compared with results from simulation software, and a way of applying the analytic solution of the electric field distribution in commercial simulation software is given.