Pu Du Ming Tai Zu Chang Juan, collected in Tibet Museum, is the earliest existing long scroll of the Ming Dynasty in China. At 4 968 cm long and 66 cm wide, it contains colorful pictures and detailed inscriptions. The pictures have lifelike descriptions of figures and architecture, and the inscriptions are written in five characters, showing rich historical and cultural value. Through a long history of more than 600 years, the long scroll had developed serious diseases and needed urgent conservation and restoration. In order to carry out the work scientifically and effectively, we made a comprehensive analysis of the mounting shape and technique for the long scroll, finding that it was generally mounted in a traditional Chinese mounting way. The exception is that the upper and lower edges of the long scroll were wrapped with red and green silk fabrics and the long scroll was backed with colorful Jiaxie, showing typical regional characteristics of Tibet. The red and green silk fabrics and colorful Jiaxie were used to reinforce the long scroll and also serve the function of decoration. They are a physical witness of the combination of Han and Tibetan mounting techniques. We also made a comprehensive assessment of the scroll’s main diseases, including wear, moth damage, fracture, crease, stain, pigment loss and improper restoration, etc. Fracture and pigment loss are related to the mounting shape. The texture of Jiaxie is rough and the red and green edge wrappings cause great thickness differences between the upper and lower edges of the long scroll and its middle part. This is why pigment fell off more seriously in the upper and lower areas than in the middle. Therefore, taking effective measures to reduce the continuous pigment loss while retaining the original mounting shape will be an urgent problem to be solved. Furthermore, we also made a comprehensive study of the painting and mounting materials using a variety of non/micro-destructive detection measures such as video microscopy, Raman spectrometry, portable X-ray fluorescence spectrometry, fiber optic spectrometry and hyperspectral imaging. The results show that 1) the painting paper of the long scroll (made from Edgeworthia chrysantha Lindl, flat and compact, with curtain lines which is unique to handmade paper), belongs to traditional Chinese handmade paper; 2) there are three kinds of raw materials used for the backing paper:mulberry bark, textured bark and bamboo; 3) the main color materials of the painting are mainly mineral pigments (mixed with plant pigments):the blue pigment is azurite, the green one malachite, the bright red one cinnabar, the pink one composed of lead white and a certain plant pigment, the orange one miniumite and a mixture of lead white and miniumite, the yellow one ochre, and the white one lead white. The pigment layer is thick but pigments have fallen off in some areas. The colorful Jiaxie and red and green edge wrappings were dyed with plant dyes such as hematoxylin, indigo and those from Sophora japonica. Plant dyes fade easily in water, so the fixation and cleaning methods need to be further studied before restoration. According to the comprehensive research, the historical value of the long scroll has been scientifically revealed, and its structure and materials clarified for the first time. The results could provide a scientific basis for the selection of materials and methods for its conservation and restoration in the future.