At present, with the growing demand for document production time identification at home and abroad, a large number of acts of forgery of document production time have emerged in the judicial identification activities, which has brought great challenges to the document judicial identification work and judicial trial. In order to meet this challenge, ensure the accuracy of document production time inspection results, and solve the problem of the time for the formation of seal, fingerprint and impression on documents. The author uses direct contact between ink (mud) and paper, the diffusion area, shape and overall speed of ink (mud) molecules were observed under the fluorescence with wavelength of 645-695nm. Combined with the factors affecting the diffusion change of ink (mud) molecules, the relative formation time of stamped seal, fingerprint and imprint on paper was judged by the diffusion area and overall speed of oil marks, and the differences were distinguished by the diffusion shape and physical and chemical analysis. (slurries). The analysis results not only help us understand the various factors that affect the diffusion form and speed of ink (mud), but also solve the relative formation time of stamped and imprinted fingerprints and imprints on paper, distinguish the diffusion form and type of different seal imprints, and distinguish the composition of ink.