This study develops a semi-empirical model of an alkaline water electrolyzer (AWE) based on thermodynamic and electrochemical principles to investigate cell voltage behavior during electrolysis. By importing polarization curve test data under specific operational conditions, eight undefined parameters are precisely fitted, demonstrating the model’s high accuracy in describing the voltage characteristics of alkaline electrolyzers. Additionally, an AWE system model is introduced to examine the influence of various operational parameters on system efficiency. This innovative approach not only provides detailed insights into the operational dynamics of AWE systems but also offers a valuable tool for optimizing performance and enhancing efficiency, advancing the understanding and optimization of AWE technologies.