Porcelain green paper is a famous processing paper in ancient China, and the relic made of porcelain green paper is often museum treasure. There are few records and researches on porcelain green paper, and there is a lack of systematic knowledge of its composition and production technology, making it difficult to carry out scientific protection and restoration of relics made by porcelain green paper. In order to further deepen the understanding of ancient porcelain green paper, three-dimensional video microscopy, Raman spectrometer, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and fiber analysis were employed to analyse the raw materials and manufacture process of one early Ming dynasty porcelain green paper sample. The result indicated that the dye on the sample matched the Raman peak position of indigo, and in the range of 1 570~1 701 cm-1, the stretching vibration of the CC bond, CO bond and N—H bond conjugate system is the characteristic absorption peak of indigo dye molecules. The sample’s strong Raman peak at 1 570 cm-1 is consistent with the Raman spectral characteristics of indigo, so it can be identified as indigo, which is also consistent with a long history of planting bluegrass and extracting indigo as a dye in China. The scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analysis indicated that the main elements of paper such as S, Ca, Al, Si, and Mg should come from filler or coating. The paper has been filled and coated in order to improve the paper opacity, permeability, and gloss, but also ruled out the possibility that the sample blue dye is azurite, lapis lazuli or natural ultramarine blue. There are transverse nodules on the fiber wall, a colloidal membrane on the outer fiber wall, a small amount of calcium oxalate crystal in the fiber, and more yellow amorphous wax on the fiber. These characteristics are similar to that of tapa and mulberry bark fibers. Therefore, the base paper of porcelain green paper should belong to the bark paper, the strength of the bark paper fiber is relatively strong, so it is not easy to hydrolyze in the dyeing process. Therefore, the production process of the porcelain green paper is as follows: indigo dye is dyed on one side of the bark paper filled and coated, then superimposed up and down. This study can deepen the understanding of the materials and technology of Ming porcelain green paper making and provide a basis for the research, protection, restoration and reproduction of porcelain green paper relics.