The invention discloses a method for detecting plastid pigment in tobacco by combining supramolecular solvent extraction with magnetic solid phase extraction. The method uses a supramolecular solvent composed of tetrahydrofuran and fatty acid and a magnetic mesoporous silicon nano-material to extract plastid pigment, and combines high performance liquid chromatography to determine the content. The magnetic mesoporous silicon nano-material has good dispersion in the supramolecular solvent, and has good adsorption performance to plastid pigment. In addition, an external magnetic field is utilized for rapid separation. Compared with other traditional methods, the method provided by the invention has the advantages of high detection sensitivity, low cost, simple operation, fast separation speed, reusability of magnetic nano-material, green and environmental protection, and has wide application prospects.