In order to improve the accuracy of leakage volume calculation of product oil pipelines, the error analysis of the input parameters used to calculate the leakage volume of product oil pipelines is carried out, including the time lag error of the pipeline operation data, the numerical error of the pipeline inner diameter and the numerical error of the oil physical properties. Through the sensitivity analysis of the input parameters, it is found that the leakage volume is the least sensitive to flow rate. The variation rate of pipeline leakage is positively correlated with time lag rate, pressure change rate and inner diameter change rate, while it is negatively correlated with flowrate change rate. The sensitivity of pipeline leakage volume to each input parameter is different within the range of variation rate of parameters.