A complexometric extraction method of extracting 6nitro1 and 2azoxynaphthalene4sulfonic acid in its mother solution is studied. At the room temperature, taking 30(v) trioctylamine(N235) chloroform solution as an extractant, when the extractant and mother solution volume ratio is 1:1 and extracting 60 minutes, the extraction yield can reach 96.1. Using 12(m) NaOH solution as a strip agent, when the organic phase and strip agent volume ratio is 2:1 and stripping 60 minutes, the strip yield can reach 94.3.