The invention discloses a positive and negative stiffness parallel three-translation vibration and impact isolation platform, and belongs to the field of the multi-axis vibration control technology and multi-axis vibration control devices, which comprises an upper platform (1), a lower platform (9), eight elastic branched-chain structures and a silica gel magnetorheological damper (11), wherein the eight elastic branched-chain structures are fixed between the upper platform (1) and the lower platform (9) two by two in an orthogonally symmetrical four-point supporting mode; the axes of the two elastic branched-chain structures of each point are vertical mutually; and the silica gel magnetorheological damper (11) is arranged in the geometric center between the upper platform (1) and the lower platform (9). The positive and negative stiffness parallel three-translation vibration and impact isolation platform can be widely used for instruments and equipment in fields of aviation, space flight, weapons, vehicles, ships, construction, nuclear industry, mechanical industry, optical industry, semiconductor industry, photosensitive chemistry and the like, and has the advantages of large carrying capacity, high stability, small volume, low natural frequency, controlled damping, low cost of manufacturing and maintenance and the like.