The invention belongs to the field of lubricating oil and particularly relates to a non-sulfur phosphorus organic magnesium additive and anti-oily sludge lubricating oil containing the additive special for taxies. The non-sulfur phosphorus organic magnesium additive is prepared by the steps of weighing a certain amount of magnesium oxide powder, dissolving the magnesium oxide into a sulfuric acidsolution, slowly dropwise adding C6-C12 linear or branched dialkyl amine, heating to 40-60 DEG C, reacting for about 90 minutes, carrying out reduced pressure distillation, and drying, so as to obtaina dialkyl amine magnesium complex. The lubricating oil containing the additive special for the taxies is capable of improving the oxidation resistance of the lubricating oil of the taxies and has very strong acid neutralization capacity, the generation amount of oily sludge is reduced by 10%-15% than the generation amount of the lubricating oil of the taxies in the market, the average oil changeperiod is more than or equal to 3000km, and the economy can be increased by 40% or above.