Abstract: In view of the need for reasonable determination of allowable emission limits in China's emission permit system, 88 printing and dyeing enterprises in Nantong City were taken as the research object, and the traditional discharge performance accounting methods and baseline setting methods were adopted to determine the discharge performance of printing and dyeing enterprises based on the actual emission level. Meanwhile, the allowable limits of printing and dyeing enterprises were determined under three scenarios of strong, medium and weak discharge reduction from a hypothetical quantitative perspective. The discharge reductions of chemical oxygen demand (COD_Cr), ammonia nitrogen (NH₃-N), total nitrogen (TN) and total phosphorus (TP) under the three scenarios were projected. The results showed as follows: 1) The maximum average value of the actual discharges of COD_Cr, NH₃-N,TN and TP in 88 printing and dyeing enterprises did not exceed 34.46% of the allowable discharges, the permissible discharge of major water pollutants in Nantong printing and dyeing enterprises had great potential for verification and reduction. 2) 95% and 99% quantile values of the 4 pollutants from 88 printing and dyeing enterprises obtained by the quantile value method were equivalent to the corresponding performance values of P95 and P99 obtained by the normal distribution analysis method. 3) Comparing the numerical reference lines obtained by the quantile value method and the normal distribution analysis method with the actual average and standard performances of 88 printing and dyeing enterprises, it was found that as to the four pollutants, at least 71.59% of the enterprises were below the average performances, 17.05% of the enterprises were between the average performances and the 95% quintile, and 2.33% of the enterprises were between the 95% quintile and the standard performances. 4) Based on the three discharge reduction scenarios of weak, medium, and strong, the projected discharge reductions for four pollutants were 2.08%-5.99%, 11.73%-20.05% and 23.24%-36.04%, respectively.