The invention discloses a quasi-zero stiffness-based vibration isolator, and belongs to the field of ultra-precise vibration attenuation. The vibration isolator is characterized in that an magnetorheological elastomer relatively low in stiffness is connected in parallel on the basis of taking a slotting belleville spring having a negative stiffness displacement region as a main elastic component;stiffness of the magnetorheological elastomer is regulated by a stiffness regulating device, so that a whole vibration isolation system connected in parallel by the slotting belleville spring and themagnetorheological elastomer under a load meets the need of quasi-zero stiffness under a certain working displacement region, and a possibility is provided for realizing low inherent frequency, high load-carrying capacity and small deformation required by the precise vibration isolation system.