The existing soot models are either too complex and can not be applied to the intal combustion engine,or too simple to make calculation errors.Exploring the soot model becomes the pursuit of the goal of many researchers within the error range in the current computer speed.On the basis of the latest experimental results,TP (temperature phases) model is presented as a new soot model to carry out optimization calculation for a high-pressure common rail diesel engine.Temperature and excess air factor are the most important two parameters in this model.When zone temperature T＜ 1 500 K and excess air factor Φ＞0.6,only the soot precursors-polycyclic aromatic hydrocarbons(PAH) is created and there is no soot emission.When zone temperature T ＞ 1 500 K and excess air factor Φ＜0.6,PAHs and soot source terms (particle inception,surface growth,oxidation,coagulation) are calculated.The TP model is then implemented in KIVA code instead of original model to carry out optimizing.KIVA standard model and experimental data are analyzed for the results of cylinder pressures,the corresponding heat release rates,and soot with variation of injection time,variation of rail pressure and variation of speed among TP models.The experimental results indicate that the TP model can carry out optimization and computational fluid dynamics can be a tool to calculate for a high-pressure common rail directed injection diesel engine.The TP model result is closer than the use of the original KIVA-3V results of soot model accuracy by about 50％ and TP model gives a new method for engine researchers.