A low cost polyacrylate superabsorbent hydrogel (SAP) was synthesized by aqueous solution polymerization. Its absorbency and salt-tolerance were studied subsequently. The results showed that the resin had a high water absorption rate of 220 g/g and 36g/gin water and salt solution, respectively. Then the hydrogel was suffered 60 ℃ high temperature to characterize the water retention. It showed that the resin have the ability to sustain water more than 720 minutes at high temperature. After repeated adsorption and discharge for five times, the adsorption amount can still reach 95.55% and 90.12% of the first adsorption amount respectively, demonstrating a good recycling adsorption performance. The high water absorbency was due to the synergistic effect of hydrophilic groups in the resin and osmotic pressure in the mesh. The presence of ions is the main reason for the decrease of water absorption ratio, but it still showed a high water absorption property, indicating that polyacrylic resin has a certain salt tolerance. The adsorption kinetics and diffusion kinetics of the resin in water and salt solution were studied. The diffusion kinetics showed that the polyacrylic acid in water was non-fickian diffusion, which was the main reason for the fast adsorption rate. Fickian diffusion was consistent in 0.9wt%NaCl solution, that is, metal ions played a leading role in the diffusion of polymer. The hydrogels with high water absorption and good water retention properties are expected to be used as water retention agents in agriculture, gardens and other fields.