For studying total reflection through effect of electromagnetic wave in 1D flat-panel photonic crystal,the transition matrix method is adopted and the transmissivity of electromagnetic wave is studied when incident angle is greater than full reflection angle.Total reflection through effect is found in the transmission wave.Response curves of the through effect versus quantum number of mode,response curves of the through effect versus period and response curves of the through effect versus thickness of flat-panel are obtained.They offer the theoretical basis for designing the high-quality filter.