Abstract: A new oil-soluble plugging workover liquid with low solid phase was prepared for application in high temperature and high salinity reservoir.Different single agents were selected in experiment, and according to the result the best formula was optimized:purified formation water +1 wt%XF clay stabilizer +0.01 wt% TF-280 Drainage agent +0.7 wt% disodium EDTA ferric ion stabilizer +1.0 wt% KY-6S filtration reducer +4 wt% oil soluble plugging agent(quality ratio of C₉ petroleum resin and C₅ petroleum resin is 1.5:1.0) +0.030 wt% AES dispersant.The optimized workover fluid properties such as apparent viscosity, static suspension time, high temperature and high pressure water loss(93 ℃, 3.45 MPa), retention rate of 24 h temperature resistance viscosity, temporary plugging rate and core permeability damage rate were evaluated.The results showed that the optimized workover fluid properties are better than the industry standard SY/T 5834-2014, and the workover fluid can be well used for workover in high temperature and high salinity reservoir.