Abstract: According to the low precision problem caused by neglecting the magnetization process of the ignition coil core in tradition methods,moving least squares (MLS) is applied to fit the magnetization curve based on the local approximation theory,meanwhile,the gross errors of measured data are detected and rejected based on absolute errors threshold of the first fitting,then the repaired data are applied to the second curve fitting.The total average relative errors are less than 0.53%.Furthermore,the fitted curve is substituted into the simulation model of ignition coil,the value and waveforms of ignition current,spark time,and ignition energy are calculated.Comparison of result verifies the validity and rationality of the algorithm,which provides a theoretical basis for performance analysis and structure design of ignition coil.