Abstract: To determine accurately the leakage volume when leaking occurs in the oil pipeline, filtration theory andhydrodynamics can be used to establish the numerical model for leaking of oil in soil. Marginal curve of oil-immersed soilis determined to be y=ax², which can be rotated for one round around the y-axis before determination of volume of oilimmersedsoil by using volumetric equation for definite integral rotary body. With the estimated volume of oil-bearing soil, density and oil contents of oil-immersed soil per unit can be obtained through multi-point sampling in different layers in ringconfiguration to estimate total volume of leaked oil. In this way, total oil volume of the oil pipeline can be determined. Withless interference, this method has error of approximately 3%.