In order to make the large load vibration isolation system reach a lower natural frequency and lower transmission rate,the vibration isolator usin g parallel positive stiffness and negative stiffness is designed for the large load vibration isolation system.The method that negative stiffness generat or′s load increment has the opposite direction to the deformation increment is used.The negative stiffness device characteristics are different from positive stiffness device.The stabilization support system is composed of negat ive stiffness generator and parallel connected large load positive stiffness generator.The system is more stable th an the normal system.It can effectively reduce the system stiffness.And the system can effectively maintain a large load.A large-scale air spring vibration isolation platform dynamics model which uses the method of absolute di splacement feedback is built.And the impact on motion amplitude response with th e large-scale air spring vibration isolation platform is analyzed.The experimental results show that the root mean square o f vertical velocities is decreased from 5.7μm/s to 2.1μm/s and the transmissibility in resonance region is decreased by 10dB.It can effectively solve the problem of passive control not very effective in the low frequency region.