Abstract: According to the conditions of bubble nucleation and onset of significant void, the accurate transformation requirements for defining flow boiling were proposed. And the boiling heat transfer numerical model was established based on the framework of boiling homogeneous flow model. The accuracy of the numerical model was validated using the Robinson experimental data. Then the temperature field of cylinder head was predicted with the model. Compared with the engine measured temperature field, the predicted results of the new boiling numerical model are more close to the actual test temperature. And the maximum error of fire face temperature is less than 7%.