Photonic modulators are fundamental photonic devices that use external energy to alter the characteristics of optical signals, primarily enabling precise control over physical parameters such as amplitude, frequency, and phase. Integrated photonic chips based on these modulators, leveraging their high bandwidth, high-speed signal processing capabilities, and extremely low power consumption, have become the core hardware platforms for future optical communication, interconnects, and computing. Technological advancements in this field have consistently attracted significant academic interest and R&D investment in recent years. While traditional research has focused on modulation speed, current demands for miniaturization and energy efficiency are gradually shifting the emphasis toward modulation efficiency. This article systematically elucidates the mechanisms for optimizing the energy efficiency of photonic modulators, with particular emphasis on a comparative analysis of phase modulators based on silicon, Ⅲ-V compounds, ferroelectrics, synthetic polymers, and graphene. Through multi-dimensional performance evaluation and mechanism analysis, it provides a reference for forthcoming innovations in efficient photonic modulation devices.