The invention discloses a method for improving damping force of an extrusion type magnetorheological fluid passive vibration isolation device and the vibration isolation device. A plurality of permanent magnets with through holes are arranged in a manner that magnetic poles are different from one another to form a plurality of cavities, and the through holes in the adjacent permanent magnets are arranged in a staggered manner; magnetorheological fluid flows in or out of the cavities and extrudes suspended particles to form chain-shaped arrangement, the chain-shaped arrangement under a magneticfield forms stopping power of the magnetorheological fluid when being extruded, part of magnetorheological fluid of the prior stage of cavity is extruded into the next stage of cavity, and the sum ofthe stopping power of all cavities is the damping force of the extrusion type magnetorheological fluid passive vibration isolation device. The method has the beneficial effects that the defects and shortcomings that in the working period of an existing semi-active magneto-rheological damper, rigidity is small, damping is rapidly lost during outburst power supply faults, dependence on the electricenergy exists, and corresponding working components are poor in radiating capacity are overcome.