In the exploration and development process of deep oil wells in Dabei，Keshen and Bozi blocks of Tarim oilfield， high-pressure salt water layer is often drilled，which makes the performance of drilling fluid worse or even damaged，seriously affecting the smooth drilling operation. Through testing the influence of salt water intrusion on the performance of oil-based drilling fluid，the mechanism of salt water intrusion was analyzed，and the corresponding salt water intrusion maintenance scheme was given. The results showed that the viscosity of the system first decreased and then increased due to salt water intrusion of oil-based drilling fluid. At 20% salt water intrusion，the viscosity decreased from 118 mPa·s to 96 mPa·s. At 30% salt water intrusion，the viscosity began to rise，and at 50% salt water intrusion，the viscosity exceeded the range of the viscometer. The emulsion-breaking voltage decreased gradually. When the salt water intrusion amount increased from 0 to 60%，the emulsion-breaking voltage drops from 468 V to 90 V. When the salt water intrusion was less than 10%，it was recommended to maintain normally and supplement appropriate main and auxiliary emulsifiers. When the salt water intrusion amount was 10%—30%，it was suggested that the drilling fluid should be separately treated and appropriate diesel oil and treating agent should be supplemented. When the salt water intrusion amount was above 30%，it is recommended to collect and treat drilling fluid on the ground. The reasonable choice the drilling fluid maintenance program was conducive to reducing the probability of occurrence of complex downhole conditions.