To reveal the signal modulation behavior of inductive sensors under the influence of measurement system parasitic parameters and complex electromagnetic environments, and to provide theoretical support for the optimization of measurement system design, this study systematically investigated the signal modulation mechanism and its suppression strategies through an integrated approach combining theoretical analysis, modeling, simulation, and experimental validation. Firstly, based on Maxwell’s electromagnetic field theory, the formation mechanism and physical nature of parasitic parameters such as inter-wire stray capacitance were elucidated, and an equivalent circuit model incorporating distributed parameters was established. Subsequently, using the Multisim simulation platform, electromagnetic interference coupling paths were reconstructed to quantitatively analyze the influence patterns of interference sources with different characteristics and stray capacitance on signal modulation depth, with design improvement measures proposed based on theoretical insights. The research results demonstrate that design improvements to the measurement system can significantly mitigate signal modulation behavior. This outcome provides a theoretical basis and technical support for the anti-interference design of nuclear instrumentation and control (I&C) systems, proving particularly valuable for electromagnetic compatibility optimization in long-cable transmission scenarios. CLC number: TL331 Document code: A