NOVELTY - Preparing epoxy toughening diluent using solar wafer cutting liquid waste, comprises: (a) processing the solar wafer cutting liquid waste; and (b) producing epoxy toughening diluent; where the raw material comprises 1000 pts.wt. of solar wafer recovering cutting liquid, 1800-2000 pts.wt. of epoxy chloropropane, 2-3 pts.wt. of boron trifluoride diethyl ether or stannous octoate, 320-350 pts.wt. of the liquid caustic soda, 20-40 pts.wt. of the liquid caustic soda, 1000-1100 pts.wt. of methylbenzene, 1-10 pts.wt. of later catalyst, and 1-2 pts.wt. of sodium dihydrogen phosphate.    USE - The process is useful for preparing epoxy toughening diluent using solar wafer cutting liquid waste (claimed).    DETAILED DESCRIPTION - Preparing epoxy toughening diluent using solar wafer cutting liquid waste, comprises: (a) processing the solar wafer cutting liquid waste: adding tap water in the solar wafer cutting liquid waste by proportioning; stirring with a high speed stirring machine for 1 hour; separating silicon carbide with a centrifugal separator; separating silica powder in the solar wafer cutting liquid waste using a pressure filter; acid washing, alkali washing, drying and wind selecting and the silicon carbide to remove iron; processing the surface thereof; reusing the silicon carbide in solar water cutting; adding the solar wafer cutting liquid waste that is separated and removed of the silicon carbide and the silicon powder in the polyacrylamide, lime water to be stirred by the stirring machine for 1-2 hours; and then adding to a deposition pool; after deposition, filtering the supernatant liquor with a filter; pressing and filtering the sublayer deposition with a pressure filter; processing the filtered and pressed materials as waste; recycling the pressed and filtered liquid; filtering the bed with silicon iron and ferromanganese iron to separate iron; after separation, continuously entering an ion exchange device to process the ion impurities; after the process, distilling to obtain solar wafer recovering cutting liquid; and (b) producing epoxy toughening diluent: putting the solar wafer recovering cutting liquid in a reaction kettle; adding boron trifluoride diethyl ether or stannous octoate catalyst in the reaction kettle; stirring; after 20-40 minutes, increasing the temperature to 45-55 degrees C; dripping epoxy chloropropane by proportioning; controlling the dripping temperature to 45-55 degrees C; after dripping is over, keeping the temperature of 60-80 degrees C for 3-4 hours; then increasing the temperature to 110-120 degrees C; eluting the epoxy chloropropane at a normal pressure; continuously reducing the pressure to elute the epoxy chloropropane until it is clean; then dripping liquid caustic soda with a concentration of 48%; controlling the temperature of 35-45 degrees C; dripping until the pH value is 10-11; keeping the temperature for 1-1.5 hours; then adding methylbenzene and stirring for 30-40 degrees C; layering and leaking the lower layer salt water; adding later catalyst benzyl triethyl ammonium chloride; and continuously dripping the liquid caustic soda with a concentration of 10%; controlling the temperature of 45-55 degrees C for 2 hours; then releasing the water containing soda; cleaning with purified water for one time; and adding sodium dihydrogen phosphate to adjust pH to 7-8; releasing the lower layer cleaning water; distilling to elute the methylbenzene until a negative pressure has no cut fraction at a temperature of 115-125 degrees C; where the negative pressure is 0.1 MPa; filtering by a filter to obtain the product; where the raw material comprises 1000 pts.wt. of solar wafer recovering cutting liquid, 1800-2000 pts.wt. of epoxy chloropropane, 2-3 pts.wt. of boron trifluoride diethyl ether or stannous octoate, 320-350 pts.wt. of the liquid caustic soda with a concentration of 48%, 20-40 pts.wt. of the liquid caustic soda with a concentration of 10%, 1000-1100 pts.wt. of methylbenzene, 1-10 pts.wt. of later catalyst, and 1-2 pts.wt. of sodium dihydrogen phosphate.