Based on the photonic bandgap structures of one-dimensional photonic crystals,the method is optimized to make the constructed omnidirectional photonic bandgaps as large as possible,and the idiographic criteria of optimized models are proposed.The criteria are different depending on whether the one-dimensional photonic crystals used in the method have their own omnidirectional photonic bandgaps or not.Then the formulae to quantitatively calculate the parameters involved in the criteria are derived.At last,a combined structure of four one-dimensional photonic crystals is calculated by using the transfer matrix method to check the criteria of combination,and get predicted results.