In order to meet the demand of heavy oil reservoir plugging control，a konjac powder gel system was prepared by using the konjac powder as the main agent，chromium acetate as the crosslinking agent，sodium lignosulfonate as the delayed crosslinking agent，sodium sulfite as the oxygen scavenger，and partially hydrolyzed polyacrylamide（HPAM）as the structural strengthening agent. The formula of this gel system was as follows 200 g distilled water + 0.5% HPAM + 0.6% konjac powder +0.7% chromium acetate +0.4% sodium lignosulfonate +0.25% sodium sulfite. The temperature resistance，salt resistance，long-term stability and plugging performance of the gel system were investigated. The results showed that when the shear rate was 10s-1，the gel viscosity at the temperature of 120℃ was 9744.77 mPa·s；and when the temperature rised to 150℃，the gel viscosity remained about 4352.36 mPa·s；when the salinity reached up to 1.4 g/L，the gel viscosity was about 10000 mPa·s；after heating at 85℃for 10 d，the gel viscosity decreased from 3023.5 mPa·s to 2350.7 mPa·s，indicating that the gel system had good temperature resistance，salt resistance and long-term stability. The plugging experiment results showed that when 0.5 PV konjac powder gel system was injected into the core of sand-filled pipe with permeability of 4.1763 μm2，the plugging rate was as high as 98.35%，and the breakthrough pressure was as high as 5.860 MPa，which indicated that the gel system had good plugging performance and was expected to be applied to plugging adjustment in heavy oil reservoirs.