The invention discloses a sacrum spreader which relates to a sacrum fracture spreading instrument, belongs to the technical field of an orthopaedics bone-setting instrument and is used for solving the problem of lacking the special spreader for treating squeezed sacrum fracture, etc. The sacrum spreader is a strip plate, the central region of the plate surface bulges upwards and nail holes are distributed on both ends of the plate surface. Block nails are additionally arranged at the inner side of the hail holes arranged on both ends of the strip plate; the strip plate can adopt a bilateral motion butt-joint structure that can be the types of hinge joint, screw thread spinning joint and trough plate splicing, etc. The symmetrical sacrum can be spread by elastic deformation or flexible displacement. The sacrum spreader has concise whole modeling and is easy to be attached and fixed on the sacrum. As the sacrum spreader has various types, the selection is easy according to using requirements, the installation, the blockage and the adjustment of the spreading degree are convenient and accurate, thus better meeting the practical spreading need of the squeezed sacrum facture, etc. Therefore, the time consumption of an operation can be greatly reduced and the effect of the operation is improved, so the sacrum spreader is suitable for treating the squeezed sacrum fracture, and the like, as a therapeutic device.