In order to obtain the performance characteristic of low viscosity cellulose and polymer with high concentration and high molecular weight blend system，the viscoelasticity and bearing strength after curing of plugging system which was composed of partially hydrolyzed polyacrylamide（HPAM），cellulose，chromium acetate cross-linking agent and pH regulator（NaHCO₃）were investigated by using stress controlled rheometer，viscometer，scanning electron microscope and self-made gel slug pressure testing device. The results showed that the storage modulus of HPAM aqueous solution increased with increasing molecular weight. The viscoelasticity of HPAM aqueous solution could be improved significantly by the addition of crosslinking agent and cellulose with low viscosity. Both the viscosity and bearing strength of this system increased with increasing concentration of cellulose，while that decreased with increasing concentration of NaHCO₃ because the cross-linked rate was delayed by NaHCO₃. The system which was composed of 25 g/L HPAM，1500 mg/L low viscosity cellulose，100 mg/L chromium acetate crosslinker and 20 mg/L NaHCO₃ had good pumping performance and salt tolerance，and its viscosity was lower than 2 Pa·s when the pumping time was 90 min. The bearing strength of the curing system was 0.5 MPa/m at reservoir temperature（70℃），which met the requirements of plugging in sealing operation. In the L-357 well plugging construction，the injection pressure was up to 11.9 MPa，and the extrusion capacity was 6 m³. After the completion of the construction，the pressure loss test of the leakage section was 15 MPa，and the pressure in 30 min remained the same.