<p>The requirements for isolating outer vibration and suppressing inner disturbances are increasingly stringent and even approaching extreme limits in integrated circuit manufacturing, precision measurement, scientific experiments, etc. In comparison with passive isolation, active control methods can significantly enhance vibration isolation performance. However, different control strategies are mainly effective in different frequency domains, and performance may deteriorate in some frequency domains due to sensor noises. Active vibration isolation based on absolute-relative dynamic stiffness control via multi-sensor information fusion is proposed in this paper. This method can substantially improve vibration attenuation capability and position stability performances in broad bandwidth, with a particular focus on improving the resonance peak suppression capability in the ultra-low frequency domain. First, the effects of different control strategies on vibration isolation in different frequency domains are analyzed, and the hybrid control strategy is proposed by using both absolute relative signal feedback. Considering the noise characteristics of absolute velocity sensors and relative displacement sensors, different filters are accordingly adopted to improve vibration isolation performance. A one-dimensional experimental platform is established to conduct vibration control experiments under different configurations. The results demonstrate that vibration isolation performance across a wide frequency range can be significantly improved, and the proposed method further proves effective for micro-vibration systems. Typically, transmissibility can be reduced to as low as −30 dB at 1 Hz and −48 dB at 2 Hz, with guarantee of less than −50 dB within 10–50 Hz. Additionally, compliance results show 10–40 dB performance improvements across the broad frequency range (0.1–100 Hz) compared with the passive system.</p>