This article discusses a method for synthesizing an environmentally friendly calcium oleate detergent using vegetable oil instead of mineral oil as the raw material. Reaction conditions including the molar ratio of total lime [Ca(OH)(2) and CaO] to oleic acid, the molar ratio of Ca(OH)(2) to CaO, the carbonation temperature, the amount of methanol, the molar ratio of water to CaO, the gas flow rate of CO2, and the molar ratio of injected CO2 to total lime [Ca(OH)(2) and CaO] were optimized. Using the optimized conditions, a high-alkali calcium oleate solution with a total base number (TBN) of 376 mg of KOH/g and an overbased calcium oleate solution with a value of TBN = 420 mg of KOH/g could be obtained.