With properly chosen structural parameters, the transmission spectra of the mirror symmetrical model of photonic crystal (AB)m (CD)n (BA)m is calculated by means of transfer matrix method. When the transmission band of photonic crystal (CD) is inside the band gap of photonic crystal (AB)m (BA)m, both sharing the same central frequency as their symmetry centers, mirror symmetrical photonic quantum well is formed. At both sides of the central frequencies in the reduced units in the transmission spectra of the well, there are odd resonance-peaks, which symmetrically distributed and orderly localized, and show an obvious quantization effect for transmission-peaks. The number and location of the transmission peaks can be modulated by changing the number of period n of photonic crystal (CD). This can be used for designing the adjustably odd-passaged optical filters.