The invention discloses a self-feedback three-stable state variable stiffness micro-vibration isolation device based on PVC Gel. The self-feedback three-stable state variable stiffness micro-vibrationisolation device comprises a machine frame, a compliant mechanism and a vibration isolation mechanism. The vibration isolation mechanism is arranged at the machine frame in a circumference arraying mode. The compliant mechanism is connected with the vibration isolation mechanism. The machine frame comprises a connecting block, a connecting ring and an installation supporting bracket. The compliant mechanism comprises a supporting beam, a main beam and a center block. The vibration mechanism comprises an adjusting shaft and a PVC Gel unit arranged at the adjusting shaft and used for absorbingtiny energy. The PVC Gel unit comprises a negative plate, a polyvinyl chloride gel film, a mesh layer and a positive element. The steady-state characteristics of the compliant mechanism are changed bysmall displacement, and therefore stiffness can be significantly regulated. Better performance of active control can be achieved with small energy loss, and better vibration isolation performance isachieved. Structure is simple, weight is low, energy consumption is little and reliability is high.