Conventional acrylamide crosslinked polymer had poor temperature and salt resistance，and would harden under high temperature and high salinity formation conditions，resulting in poor deformation and failure of profile control in deep formation. In order to solve these problems，the temperature and salt tolerant copolymer particle was prepared by introducing the functional monomers N-vinyl pyrrolidone（NVP）and N，N-dimethyl acrylamide（DMAA）into the system，using diethylene benzene as crosslinking agent，formaldehyde sodium bisulfate and ammonium persulfate as initiator and sodium soil as stabilizer. By introducing clay into the system to enhance the toughness and stiffness of polymer，the effects of monomer ratio，addition of various substances on water absorption expansion multiple and energy storage modulus of crosslinked polymer were studied. The results showed that the suitable synthesis condition of the crosslinked polymer was obtained as follows：30% monomer mass fraction，6∶4 NVP and DMAA molar ratio，0.25% diethylene benzene dosage，0.15% formaldehyde sodium bisulfate，0.15% ammonium persulfate dosage，3% sodium soil mass fraction. Through special crushing equipment and two-stage granulation，the particle size could be adjusted from 1 to 10 mm. Under the condition of 130℃ and salinity of 22×10⁴ mg/L，the crosslinked polymer particle was still in the state of water absorption and expansion，and the energy storage modulus was about 5000 Pa after standing for 90 days. The temperature and salt tolerance of the crosslinked polymer was improved.