The present invention provides a decorticator for chironji nut. The decorticator comprises: an inlet means having a hopper and feed rate controller means a vertical cylindrical casing having rotary impellers, stripped impacting device, impeller shaft, and concave surfaces a plurality of cleaning and grading means an outlet means wherein the nuts from the inlet means are pushed at a controlled speed from hopper to the cylindrical casing where they are moved by rotating impellers and fall onto the stationary concave surface covering 180° of said cylindrical casing, where the nut cracks due to the impacting force on the surface and is pushed to the another side of concave surface to remove the outer surface of nut by shearing action which are then passed through the plurality of sliding cleaning and grading means to separate the shell and kernels.
