In vibration control, signal processing, and object tracking, the acquisition of absolute displacement signals from vibrating platforms is essential. Addressing this critical need, the present study proposes a bio-inspired dynamic vibration sensor system specifically designed for absolute displacement measurement. Constructed from fundamental mechanical elements such as beams and springs, the system achieves nonlinear quasi-zero stiffness (QZS), thereby establishing a broadband inertial reference suitable for precise displacement quantification. A comprehensive theoretical analysis evaluates the influence of structural parameters on the sensor’s performance, aiming to optimize isolation characteristics and enhance measurement accuracy. To mitigate noise interference in sensor data, the square-root unscented Kalman filter (SR-UKF) is employed for dynamic state estimation, significantly improving measurement precision. The effectiveness of the proposed system is validated through extensive simulations and further substantiated by experimental results obtained from a custom-built prototype testbed, confirming both the accuracy of displacement measurements and the robustness of the filtering algorithm.