The characteristic of the overflowing ash-sluice in power plants have been analyzed. A kind of multi-functional high polymer compou nd is used to remove the pollutant in ash-sluice water and to prevent scaling. The reagent which is characterized by having a fas ter reaction speed, less feeding quantity, wider applicable range and better res ults is used as flocculant in the overflowing ash-sluice water treatment. When used in ash-sluice water as corrosion inhibitor SS<300 mg/L, pH 7～12.5，it can efficiently prevent the water recovery system from scaling and lower the scaling speed of the ash-sluice transporting system. In addition, it is characterized by having lower treatment cost, no pollution. It is good for forming a good cycle for the whole water recovery system and ash-sluice treatment system. A simple and suitable technology has been designed for the ash-sluice treatment system, In this technique, more than 3 ponds have been saved. Its successful application in different types of plants shows that the results are low investment, small site, low operating expense (the treatment cost is 0.015～0.03 yuan per m³ of water). This technique can also be used for the recovery of settling sluice water in ash ponds.