Aging oil，a by-product of oilfield surface production，has complex interface characteristic，as a result，it is difficult to be dehydrated. Using aging oil to develop lubricant for drilling fluid can make use of its emulsifying stability and avoid the difficulties of removing mud，sand and water from aging oil. The components and dosage of lubricant were optimized，and then the performance of lubricant was evaluated. The results showed that the emulsifier for developing lubricant based on aging oil was alkylphenol polyoxyethylene ether（OP-4），the wetting agent was sodium dodecylbenzene sulfonate（ABS），and the stabilizer was sodium carboxymethyl cellulose（Na-CMC）. The optimum formula was obtained as follows：100 mL drilling fluid，3 mL aged oil， 1.5 g OP-4，0.15 g ABS and 0.015 g Na-CMC. The density，apparent viscosity and sticking coefficient of mud cake of the system met the requirements of enterprise standards after the lubricant was added to the bentonite based slurry. Using aged oil as base oil to develop lubricant for drilling fluid was a feasible resource utilization scheme for aged oil.