In power system, the post-insulator is a critical apparatus which carries the conductor and also provides isolation between the conductors as well as ground. Besides, it offers mechanical support. However, extreme weather and pollution cause post-insulator flashover, which results in interruption of power supply and revenue loss. Therefore, post-insulator’s pollution flashover study is necessary. The pollution flashover voltage (FOV) is directly related to dominating metrological circumstance and how this pollution severity on the surface of insulator. Mostly, anti-pollution flashover coating is deliberated to be one of the most effective means to prevent and reduce pollution flashover. This paper investigates and compares the application of Epoxy Resin and Room Temperature Vulcanize (RTV) Silicone Rubber for enhancing the performance of ceramic outdoor (near coastal thermal plant area) insulator to defeat the effect of environmental pollution. At first, a real-time pollution performance has been carried out in controlled laboratory setup. It shows that the withstand ability of post-insulator has been 25% with Silicone Rubber coating. Subsequently, Artificial Neural Network (ANN) has been used to predict the FOV of post-insulator under wet and dry condition. It shows that critical FOV has enriched with anti-reflection coating rate. After that, post-insulator has been modeled by COMSOL multiphysics software, which is used for estimating field distribution on post-insulator. From the modeling, we found that anti-reflection coated post-insulator surface has low electrical stress than that of others.