In order to improve the water absorption ability of acrylic acid absorbent resin in salt solution and relatively high temperature environment, modified polyacrylic acid (PAA) absorbent resin was prepared by using 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS), N-vinyl pyrrolidone (NVP) and sodium carboxymethyl cellulose (CMC) as modifiers. The results showed that when the amount of acrylic acid (AA) was 21%, the neutralization degree was 66%, crosslinking agent was 0.04%, initiator was 0.5%, amps and NVP were 30% and 5.7% of AA respectively, the water absorption rate of modified PAA resin in normal saline increased from 20g /g to 91g/g, and it still absorbed 77g/g in 2000mg / L NaCl. The water absorption rate in artificial urine and artificial blood was 115g / g and 89g/g, respectively. The water absorption ratio of deionized water at 55 ℃ increased from 524g/g to 2215g/g. At 37℃,the degradation rate of modified PAA absorbent resin was as high as 72%. It can be seen that the modification can improve the water absorption, temperature resistance, salt resistance and biodegradability of PAA.