An innovative idea was proposed to prepare the overbased nano-sized calcium carbonate-calcium petroleum sulfonate in-situ the HIGEE reactor. The test sample prepared by this technology could meet the requirement of the industry standard SH0042-91 for the first-grade product on a par with similar overseas product. The test results obtained upon observation under microscope after freezing etching of specimen revealed that the crystal size of colloidal calcium sulfonate was in the range of 10-30 nm with an average size of 20 nm. The size of the detergent additive was uniform with good transmittance and fluidity. The HIGEE technology possesses five specific features as shown below: Firstly, the carbonation reaction is completed in one step with the reaction time reduced by more than 50% as compared to traditional batch reactor process along with enhanced reaction efficiency, good operability of the process and stabilized product quality. Secondly,ammonia emitted from the reaction is used as the co- promoter without the need for adding ammonia and water as promoters to simplify the promoter system along with effective and strong coupling of reactions. Thirdly, the utilization rate of Ca(OH)2 and CO2 is increased by 15% and 30%, respectively, with product yield increased by 15%, and calcium residue decreased by 65%. Fourthly, the HIGEE technology is environmental benign because of gasoline is used in this technology instead of toxic toluene and xylene. Fifthly, the dimension of HIGEE reactor is reduced by above two-thirds. The success in development of this new technology will offer new ideas and technology platform for the synthesis of metal detergent additive to lubricating oils in China.