The invention discloses a motor silicon steel sheet compactor. The motor silicon steel sheet compactor comprises a pair of clamping tiles, wherein the upper and lower ends of the clamping tiles are respectively provided with fixed discs, and each clamping tile comprises an arc-shaped clamping piece, the middle portion of the inner side of the clamping piece is provided with a positioning full groove, the two ends of the clamping piece are respectively provided with positioning half grooves, one end of the clamping piece is provided with an outwards extruded engaging extrusion, the other end ofthe clamping piece is provided with an inwards recessed engaging groove, the engaging groove is matched with the engaging extrusion, the center lines of the fixed discs are provided with motor axle holes and limiting sinking troughs, a plurality of fixed screw holes are arranged in the circumferential directions of the fixed discs, and the fixed screw holes are internally provided with fixed bolts. In the process of pressing, the silicon steel sheet is still locked by the fixed discs and the clamping tiles so as to effectively avoid displacement deviation and effectively guarantee the tool quality.