The invention discloses a method for quantitatively analyzing components in shale. The method includes steps of 1), drying selected 50g of rock cores of shale layer sections, then dividing the rock cores into a portion A and a portion B, grinding samples of the portion A until the particle sizes of the samples of the portion A are smaller than 0.2mm, and smashing samples of the portion B until the particle sizes of the samples of the portion B are smaller than 1mm; 2), weighing 0.01g-1.00g of samples of the portion A, adding excessive hydrochloric acid solution into the samples of the portion A, enabling the hydrochloric acid solution and the samples of the portion A to react completely, then washing the samples with distilled water until the samples are neutralized and drying the samples; 3), using a carbon-sulfur analyzer to analyze organic rock carbon of the samples obtained in the step 2), and determining the percentage contents W1 of organic matters in the shale; 4), grinding the treated samples of the portion B until the particle sizes of all the samples of the portion B are smaller than 40 micrometers; 5), acquiring the percentage contents of various inorganic rock minerals in powder samples obtained in the step 4); 6), normalizing the total quantities of inorganic rock facies and the organic matters and then acquiring the percentage contents of the various components. The method for quantitatively analyzing the shale has the advantages that composition of the components in the shale and the contents of the components can be accurately reflected, and the method is also applicable to comprehensive research.