The invention relates to a method for detecting oil and gas by the aid of stacked seismic data. The method includes analyzing frequency spectra of objective intervals of seismic traces beside wells and determining parameters of sliding time windows; dividing high-frequency and low-frequency portions of the frequency spectra by the aid of weighted average frequencies, and solving frequency spectral energy of the low-frequency portions by the aid of a reverse frequency weighting process; acquiring energy coefficients by the aid of ratios of the energy of the low-frequency portions to energy of the high-frequency portions of the frequency spectra; creating seismic wave attenuation factors for indicating the oil and gas containing probabilities of strata by the aid of the energy coefficients and weighting frequencies; acquiring data volumes of the seismic wave attenuation factors of work areas and identifying beneficial oil and gas containing work areas in the work areas. The method has the advantages that low-frequency enhancement and high-frequency attenuation information in the frequency spectra of the seismic data can be sufficiently extracted and utilized, accordingly, the method is favorable for highlighting existence of oil and gas layers, the oil and gas layer identification ability can be enhanced, and the oil and gas detection sensitivity can be improved.