Abstract: It is difficult to solute Powder Fluid Loss Additive into water,It need long time,the stability is poor.It effects the degree of uniformity of slurry.Dry blending is impossible.In order to solve these questions,we synthesized DSJ,new polymer,peroxide as initiator,through copolymerizing the monomers of sulfonic acid group,amide group,alkyl group,carboxyl group in aqueous solution.DSJ has a excellent ability of controlling fluid loss of slurry(less than 100 mL),it is easy to solute into water in 150 min at normal temperature,The applied temperature is wide(normal-120℃),salt tolerance is 20%;DSJ has a excellent compatibility with too many kinds of cements,thickening time can easily be adjusted;compressive resistance is high and resistance to fouling is good.It shows in the cementing projects in Hailaer Oilfield that application of DSJ can decrease transportation cost,prevent leach and bypass channel of water and gas.It is useful for improving cementing quality.