The invention relates to the field of silicon wafer wire-electrode cutting and discloses a method for recycling carborundum and cutting polyethyleneglycol in waste mortar by silicon wafer wire-electrode cutting. In monocrystalline silicon piece processing technique, a viscosity reduction agent is firstly added before waste mortar linear cutting, and then a suspending liquid part and a solid particles part are obtained by the solid-liquid separation; The suspending liquid part is added with a filter aid, then filter pressing with a plate frame, micro porous filtration, hyper filtration with hollow fiber and ion exchange are carried out sequentially, and finally, the suspending liquid is distillated in vacuum and polyethyleneglycol is recycled. Alkali reaction cleaning, water scrubber washing, centrifugalization, acid reaction cleaning, the second water scrubber washing, the second centrifugalization, the second acid reaction cleaning, drying and drying classification are carried out on the solid particles in sequence, and finally, recyclable silicon carbide particles are obtained.