Plugging agent plays a key role in the process of oil development，quality improvement and efficiency enhancement. However，there are some problems such as insufficient plugging strength，short validity period and low water plugging efficiency， which considerably affect the practical application. Therefore，the research on high-strength plugging system becomes a hot topic in oil production. In this paper，a kind of organic cross-linked gel plugging agent was developed，with polyhydroxyethylacrylamide （PHEAA）as the skeleton molecule，1，6-hexane diisocyanate（HDI）as the crosslinking agent，and a mixed solution containing N，N-dimethylformamide（DMF）and dimethyl sulfoxide（DMSO）as the solvent. The organic plugging system could undergo sol-gel phase transition under constant temperature conditions. The effects of the dosage of PHEAA and HDI and temperature on the properties such as gelation time and gel strength were investigated. Furthermore，the effect of plugging system on water plugging and profile control of sand-filled pipe was evaluated. The results showed that the strength of the gelled organic gel was proportional to the concentration of PHEAA and HDI，while the gelation time was adversely proportional to the temperature. When the dosage of PHEAA and HDI increased from 10%，2% to 16%，7%，the corresponding storage modulus increased from 991 Pa to 3100 Pa， and then the viscosity increased from 22 400 mPa s to 45 100 mPa s，respectively. In addition，accompanying with the increase of component content，the gelation time of plugging agent system obviously shortened，which reduced from 1 h to 20 min. When the temperature increased from 45 ℃ to 125 ℃，the gelation time decreased from 3 h to 13 min. The SEM scanning results showed that the state of plugging system changed from liquid film to irregular three-dimensional crosslinking network after gelation. The solid-state transition of the system was mainly attributed to the nucleophilic reaction between HDI and hydroxyl groups in PHEAA. In the sand-packing pipe plugging experiment，after injecting 1 PV liquid plugging system and heating for 6 h at 85 ℃，the plugging strength after solidifing could reach up to 26.11 MPa，showing good effect of water plugging and profile control.