Rock with oil and gas can make attenuation to seismic wave. When seismic primary wave goes throw oil and gas formation, it will engender serious attenuation. Then, the low-frequency shadow with character of low frequency and strong amplitude will appear under the reservoir. In low frequency stage, low-frequency shadow is obvious, and the power of seismic reflection wave is stronger than the power of reservoir. In high frequency stage, the power of low-frequency shadow is lower than the power of reservoir and with the frequency goes up, the power weaken. In this paper, the author chooses well SYB1 district as the research objective to study the application of low-frequency shadow technology in prediction of organic reef oil and gas reservoir. With the comparing of application character of well SYB1 and SYBc1, connected to the identification mark of low-frequency shadow technology in the prediction of oil and gas reservoir, the author finds out that low-frequency shadow technology is suitable in the prediction of organic reef oil and gas reservoir. And this study proves the low-frequency shadow technology is valid, which will be the reference frame for the reservoir prediction of the same style.