A novel copolymer was synthesized using acrylamide(AM),sodium allylsulfonate (SAS),sodium p-Styrene sulfonate (SSS) and Acrylic polyethers(APEG), it could be used as an anti-temperatureand and salt-tolerant fluid loss additive. We obtained the optimal reaction conditions, which is, m(AM):m(APEG):m(SSS):m(SAS)= 6.5:2.0:0.5:1.0, monomer concentration is 20%, dosage of initiator is 0.2%, temperature of reaction is 60℃. Meanwile, the structure of this polymer was confirmed through FTIR, the result show that the molecular sturcture of the artificial synthesis product is in accord with the ideal one. The thermogravimetric experiment indicates good therm stability of this polymer. Compared the morphology of filter cake by SEM, it could forn a thin and dense filter cake by the fluid loss agent .Moreover, the fluid loss additive had reveal good temperature resistance and salt tolerance.