Remolded sample preparation instrument and method for medium-sized coarse-grained soil shearing instrument

The invention discloses a remolded sample preparation instrument and method for a coarse-grained soil medium-sized shearing instrument. The remolded sample preparation instrument comprises a shearing box, a rack, a sample moving assembly and a sample compacting assembly, the sample moving assembly comprises a moving driving mechanism and a moving plate, and the shearing box is arranged on the moving plate; the sample compacting assembly comprises a lifting driving mechanism and a compaction mechanism, the compaction mechanism comprises a compaction guide rod, a compaction plate and a guide part which are connected with one another, and the compaction guide rod is detachably connected with the lifting part of the lifting driving mechanism; and the compaction route of the compaction plate is S-shaped. According to the invention, the shearing box is driven by the moving driving mechanism to stably move relative to the compaction plate, so that an S-shaped compaction path of the compaction plate is completed, nam