TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The recycling method comprises: either (a) extracting waste water containing butyl acetate in production of lovastatin medicine, using liquid wax as extracting agent, in which the volume ratio of extracting agent and aqueous solution containing butyl acetate is 1:1, and mixing and agitating for 20 minutes, (b) statically placing the extracted mixed liquid for 10 minutes, with volume ratio of organic phase extracting agent to the aqueous solution containing butyl acetate is 1:1, and mixing and agitating for 20 minutes for extraction, statically placing the extracted mixed liquid for 10 minutes and repeating the step for 10 times, (c) placing the finally collected organic phase in a rectifying tower, with the rectification temperature of 180 degrees C, and (d) regulating pH of strong sodium hydroxide alkaline solution to 13, where the volume ratio of high-boiling point extracting agent to the strong alkaline solution is 1:3, agitating the extracting agent and alkaline-washing for 15 minutes and then statically placing for 10 minutes, with volume ratio of the alkaline-washed extracting agent to the water washing liquid is 1:3, and then agitating the extracting agent and performing water-wash for 15minutes, and statically placing for 10 minutes; (a) extracting waste water containing butyl acetate in production of lovastatin medicine, using 200 solvent oil in high-boiling point solvent oil as extracting agent, in which the volume ratio of extracting agent and aqueous solution containing butyl acetate is 1:3, and mixing and agitating for 5 minutes, (b) statically placing the extracted mixed liquid for 5 minutes, where the volume ratio of organic phase extracting agent to the aqueous solution containing butyl acetate is 1:3, and mixing and agitating for 5 minutes for extraction, statically placing the extracted mixed liquid for 5 minutes, and repeating the step for 10 times, (c) placing the finally collected organic phase in a rectifying tower with rectification temperature of 180 degrees C, and (d) regulating pH of strong sodium hydroxide alkaline solution to 12, where the volume ratio of high-boiling point extracting agent to the strong alkaline solution is 1:5, agitating the extracting agent and alkaline-washing for 15 minutes and then statically placing for 10 minutes, where the volume ratio of the alkaline-washed extracting agent to the water washing liquid is 1:5, then agitating the extracting agent and performing water-wash for 20minutes and statically placing for 15 minutes; (a) extracting waste water containing butyl acetate in production of lovastatin medicine, using diesel oil as extracting agent, in which the volume ratio of extracting agent and aqueous solution containing butyl acetate is 1:10, and mixing and agitating for 50 minutes, (b) statically placing the extracted mixed liquid for 15 minutes, where the volume ratio of organic phase extracting agent to the aqueous solution containing butyl acetate is 1:10, and mixing and agitating for 50 minutes for extraction, statically placing the extracted mixed liquid for 15 minutes, and repeating the step for 10 times, (c) placing the finally collected organic phase in a rectifying tower, with rectification temperature of 140 degrees C, and (d) regulating pH of strong sodium hydroxide alkaline solution to 14, where the volume ratio of high-boiling point extracting agent to the strong alkaline solution is 1:1, agitating the extracting agent and alkaline-washing for 5 minutes and then statically placing for 10minutes, where the volume ratio of the alkaline-washed extracting agent to the water washing liquid is 1:1, agitating the extracting agent and performing water-wash for 10 minutes, and then statically placing for 5 minutes; (a) extracting waste water containing butyl acetate in production of erythromycin medicine, using 260 solvent oil in high-boiling point solvent oil as extracting agent, in which the volume ratio of extracting agent and aqueous solution containing butyl acetate is 1:1, and mixing and agitating for 20 minutes, (b) statically placing the extracted mixed liquid for 10 minutes, where the volume ratio of organic phase extracting agent to the aqueous solution containing butyl acetate is 1:1, and mixing and agitating for 20 minutes for extraction, statically placing the extracted mixed liquid for 10 minutes, and repeating the step for 20 times, (c) placing the finally collected organic phase in a decompressing distilling tower, where the decompressing distilling is performed at 70 degrees C at 0.1 Mpa, and (d) regulating pH of strong sodium hydroxide alkaline solution to 13, where the volume ratio of high-boiling point extracting agent to the strong alkaline solution is 1:3, agitating the extracting agent and alkaline-washing for 15minutes and then statically placing for 10 minutes, where the volume ratio of the alkaline-washed extracting agent to the water washing liquid is 1:3, then agitating the extracting agent and performing water-wash for 15minutes and then statically placing for 10 minutes; or (a) extracting waste water containing butyl acetate in production of penicillin medicine, using liquid wax extracting agent, in which the volume ratio of extracting agent and aqueous solution containing butyl acetate is 1:1, and mixing and agitating for 20 minutes, (b) statically placing the extracted mixed liquid for 10 minutes, where the volume ratio of organic phase extracting agent to the aqueous solution containing butyl acetate is 1:1, and mixing and agitating for 20 minutes for extraction, statically placing the extracted mixed liquid for 5 minutes, and repeating the step for 20 times, (c) placing the finally collected organic phase in a distilling tower with distilling temperature of 160 degrees C, and (d) regulating pH of strong sodium hydroxide alkaline solution to 13, where the volume ratio of high-boiling point extracting agent to the strong alkaline solution is 1:3, agitating the extracting agent and alkaline-washing for 15minutes and then statically placing for 10 minutes, in which the volume ratio of the alkaline-washed extracting agent to the water washing liquid is 1:3, then agitating the extracting agent and performing water-wash for 15 minutes and then statically placing for 10 minutes.