Abstract: Through sodium sulfite and ammonium persulfate (mass ratio is 1:2) as the initiator,and acrylamide (AM), 2-acrylamide-2-methyl propane sulfonic acid (AMPS), dimethyl diallyl ammonium chloride (DMDAAC), and allyl pyrrolidone (NVP) as the monomers,getting a kind of performant polymer PAADN,which can be used in the drilling mud.Bying studying the polymer synthesis,we got the optimum synthesis condition: monomer ratio of m(AM) : m(AMPS) : m(DMDAAC) : m(NVP) is 51:40:6:3, total monomers concentration is 20%, the reaction temperature is 55 ℃, pH is 7, dosage of initiator is 0.5%, the reaction time is 5 h.Evaluating the performance of the polymer showed that the infrared spectrum characteristic peaks have not shown double bonds peak，and it contains every monomer peak which we can conclude that all monomers take part in reaction; thermogravimetric analysis results showed that the polymer thermal stability is good, and it can also resist 326.5 ℃; Putting polymer in fresh water mud, salt water mud and artificial simulated seawater mud ,all of muds showing good preference.