Polymerization effluents (PME) from dry-spun acrylic fiber manufacturing are hard to degrade. This paper evaluated the distribution characteristics of PME pollutants by means of multi scale membrane filtrations, including microfiltration (5 μm and 1 μm), ultrafiltration (50 KD, 10 KD and 6 KD), nanofiltration and reverse osmosis. Scanning electron microscopy (SEM) and laser particle size analyzer (LPSA) tests were also used as assistant measurements. The majority of particles in PME are mainly categorized as supracolloidal structures. 70% of them rage from 5 μm to 20 μm with a median size of 9.99 μm. Particulate, colloidal and soluble portions contribute 7.6%, 8.2% and 75.2% to the initial COD, meaning that the soluble fraction, which is also poor in biodegradability, plays a key role in PME treatment. 26.8% of TN, mainly consisting of various acrylonitrile copolymers, exists in the colloidal portion; while 70.5% of it, mainly comprised of ammonia, cyanide and nitrile, distributes in the soluble portion. The distribution characteristics of ammonia and SO32- are similar. Respectively 92.7% and 94.7% distributes in the soluble portion.